Indiana+State+Fair+Stage+Collapse

Indiana State Fair Stage Collapse //Yong Yue, The Pennsylvania State University Class of 2017 // toc
 * Indianapolis, Indiana - August 13, 2011 **

Introduction
The Indiana State Fair is an annual fair held in Indianapolis, Indiana, celebrating agriculture, youth and education in 17 days. During the fair, the Indiana State Fair Commission (ISFC) usually holds a lot of activities including free concerts, a beer & wine exhibition, a Hoosier lottery grandstand, and more, which attract 900,000 visitors annually.

On August 13, 2011, a temporary grandstand stage was erected for a concert at the Indiana State Fairground. In the evening hours, Sugarland fans were already claiming their spots in front of the stage and in the nearby grandstand awaiting the performance. Unfortunately, at 8:46 p.m., a nearby 60-mile-per-hour wind gust slammed into the venue, kicking the temporary roof structure.The structure immediately landed among a crowed of spectators, killing seven people and injuring 58 others.

Events Leading Up to the Collapse


Prior to the event, the National Weather Service (NWS) reported that a strong thunderstorm would be moving through the Central Indiana area throughout the day and evening. Ray Allison, the ISFC's Director of Public Safety and Logistics communicated to ISFC personnel for updates via a new system which allowed for voice or test messages to be distributed on a preset list. After 7:00 p.m., he replied that we will experience heavy rain and possible high winds between 9:00 and 9:30. (Witt 2012) Figure 1 shows that Sugerland fans were already claiming their spots and awaiting the show at that time.

Fair and entertainment officials met at 8:00 p.m. to discuss operational issues related to the timing of the show, but public safety related to the weather forecast was not discussed. The few minutes after the conversation, they spoke to the band only about the forecast for rain and suggested to delay the show. However, the band wanted to go on since they play in rain frequently. Following a conversation with Sugarland 's management, it was agreed that the show was delayed to start at 8:50. Four spotlight operators climbed into their stations. (Witt 2012)

After meeting, ISFC Executive Director Cindy Hoye had a chance encounter bac kstage with Brad Weaver, a captain with the state police.Weaver expressed concerns about the dark clouds approaching the fairgrounds from the west. Captain Wear and Director Hoye discussed an evacuation plan. Director Hoye then began instructing staff to prepare for the evacuation of the grandstand area. At 8:39 p.m., the National Weather Service (NWS) issued another severe thunderstorm warning; however, neither Director Hoye or Captain Weaver received this information. Under an impression that the event's emcee was going to tell the crowd to evacuate, Weaver instead heard an unexpected announcement that was dictated to the emcee by Hoye. They head up to the stage to announce an immediate evacuation. Unfortunately, they never made it back to the stage. (Witt 2012)

Investigation & Cause of Failure


Immediately following the collapse on August 13, Indiana State Fair Commission (ISFC) retained Thornton Tomasetti (TT) to defined the engineering- based causation of the ISF structure failure and other related functions. Another two firms were contacted to provide technical information of the ISF Structure, including James Thomas Engineering (JTE), the designer of the ISF Structure, and America Sound Corporation (ASC), the manufacturer and installer of the ISF Structure. According to TT's report, the structure designed by JTE was not able to support the actual loads even missing the codes, and ASC's installation of the structure deviated from the direction calculated by structural engineers with regard to the lateral force resisting system. Figure 2 shows the collapsed structure taking on August 14.

Thornton Tomasett (TT) analyzed the ISF Structure and eventually found that the failure of the ISF Structure was caused by the inadequate capacity of the lateral force resisting system, which was contributed by guy lines connected to concrete "Jersey Barrier” Ballast, and based on testing and calculation, the lateral force resisting system of the ISF Structure was capable of resisting winds speeds ranging from 25 mph to 43 mph (depending on wind direction). There are a lot of structural problems reducing the resistance of the lateral system; in this Wiki I would like to discuss Four main causes: inadequate Jersey Barrier capacity, inadequate guy line capacity, inadequate fin plate capacity and the second effects of columns.


 * **Guy Line & Jersey Barrier Capacities**

The lateral force resisting system consists of fourteen (14) guys lines that are connected to ten (10) reinforced concrete Jersey barriers ( See Figure 3 and 4). The guy line system at the ISF Structure comprises several components, including 3/8" diameter wire rope, steel rigging shackles and synthetic webbing ratchet straps.Six (6) guy lines connected to four (4) Jersey barriers carry lateral loads in the west to east direction, and four (4) guy lines connected to two (2) Jersey barriers carry lateral loads in the south to the north direction. The wind came from the west and kicked over the roof tarp. The wind load was transferred to the eave and the ridge where the tarp was attached. The drag forces were transferred to the guy line system which in turn transfer the load to the Jersey barriers. The Jersey barriers resist drag forces through its self-weight and friction with the ground surface. Base on TT's calculation and analysis, the guy line system and the Jersey barriers installed at the ISF Structure provided insufficient resistance against both code-required loads and the wind loads of date of the event.




 * **Fin Plate Capacity**

Fin plates are the connection part between the guy lines and the main roof truss, and directly transfer wind load to the guy lines (See Figure 5). Based on TT's calculation and observation, the fin plates were insufficient to resist the guy line forces applied for both code-specified wind load and the wind loads of date of the event. In figure 6, yellow line shows the location of fin plate prior to tearing off. The failure of the bottom tube due to the bending capacity is circled in red.




 * **Second Order Analysis**

Most of temporary outdoor structures failed since the second effect of the column was not considered during the design. The temporary structural usually have very slender columns supporting the a main roof with heavy suspended entertainment equipment. Robert Chapman, the founder of Sound Mind Event, has 20 years of experience in stage assembly and equipment rigging. He analyzed video footage of the events that occurred at Indiana State Fair, and he believes that the combination of the rooftop and the additional weight of the attached equipment conspired with the high winds to bring down the structure. RWDI, a wind consultant retained by TT, determined the suspended entertainment technology equipment added 5,300 lbs of force in the east direction and 100 lbs in the south direction, for a total resultant force of 13,400 lbs on the structure and suspended entertainment technology equipment. So the second effect of the column must to be considered as a highly possible cause in this case. The capacities of the slender columns were reduced under heavy axial loads combining with high wind loads. The structure has limited lateral force resisting capacity without the guy line system installed since the columns were not braced for resisting the lateral forces (See figure 7).

Management & Organization
Although the collapse was primarily caused by the structural problem, lacks of preparedness and organization have to be considered as a reason for this tragedy. Witt Associate was separately retained by ISFC to review the state of preparedness at the State Fair, as well as the events leading up to and in response to the collapse. The following findings leading up the event was discussed by Witt Associate:


 * It was not clear who or what organization was responsible for public safety during the 2011 Indiana State Fair. As a result, there was ambiguity of authority regarding who was in charge of public safety leading up the collapse.
 * The ISFC did not use an emergency management protocol to make weather-related decisions.
 * The ambiguity of authority and lack of a formal protocol created uncertainty and confusion, which led to the ISFC's decision to allow the concert to start at 8:50 p.m.
 * The ISFC had set up a system to communicate weather forecasts but the distribution of message was limited to ISFC staffs, and did not include contractors or public safety agencies at the Fairgrounds
 * Until the chance meeting with Captain Weaver, the ISFC staff's focus on the implications of the weather forecasts on the timing of the production. The ISFC took actions to prepare for an evacuation only after Captain Weaver expressed concern.

Prevention/Recommendation

 * Temporary outdoor stage structures should be designed by a licensed design professional with experience in the design and evaluation of the structures with complex loading configurations. The design of the temporary structure should meet all code and permitting requirements of Class 1 structures, in addition to a third-party peer review if the community does not have adequate capability to perform the plan review. A Special Inspection of the completed structure should be completed by an independent licensed design professional with experience in the design and/or evaluation of temporary structures. (Thornton Tomasetti 2012)
 * Environmental and site-specific loading conditions should be analyzed for the specific structure to be erected and the suspended entertainment technology equipment to be suspended.(Thornton Tomasetti 2012)
 * Guy line anchor systems for entertainment structures should utilize fixed, mechanical anchors whenever possible. (Thornton Tomasetti 2012)
 * Working with their public safety partners, the ISFC should update its Emergency Response Plan and procedures for operations on the State Fairgrounds, and include an annex for the 17‐day Indiana State Fair. ISFC staff (and appropriate contractors) should be aware of and trained on their role in the Plan, and should participate in regular exercises of the Plan. (Witt 2012)
 * The ISFC should adopt a policy and an established a protocol for delaying, postponing, and canceling major productions. The policy should articulate that although performers may delay their performances due to concern for their personal safety and that of their crew, a venue like the ISFC has the responsibility and the ultimate authority to delay (or stop) a performance in the interest of public safety for all in attendance.and protocol The policy should be shared with all involved in productions on the Fairgrounds, including ISFC contractors, and incorporated into signed contracts with the performers. (Witt 2012)
 * The weather data should be seen by all crews, contractors rather than ISFC staffs. (Witt 2021)
 * As a result of the Indiana State Fair incident, a National Fire Protection Association (NFPA) task group now has additional information to review a s it considers the best way to establish decision-making protocols for venue managers who apply the Life Safety Evaluation (LSE), an important of NFPA 101R, Life Satety Code, that address an array of fire and non-fire emergencies and crowd safety issues. (NFPA)
 * The State Fair Commission should conduct an adequate life safety evaluation and plan prior to the event. Engineers or installer also need to consider soil conditions when placing cable anchor points for the grandstand stage. Firms should consider the protection for employees working 4 feet or more above ground level and conduct a PPE hazard assessment of the work-site. (OSHA)
 * Government inspection must occur on the temporary outside stage structures.

**Similar Cases/Lessons**
By researching data for this case study, I found that the Indiana State Fair stage collapse was not the only case happened in the summer of 2011. It was the summer's third high-profile weather-induced structural failure at an outdoor concert. A fourth stage would collapse just five days later at a festival in Belgium, killing seven people and injuring more than 40.

That summer ranks as the most frequent outdoor music season, but structural failures ar open-air venues are nothing new. In August 2009, severe weather destroyed Canada's biggest country music event when a 125-mile hail-and -thunderstorm front pummeled center Alberta. Sixty (60) mph winds toppled the temporary stage at the Big Valley Jamboree, one dead and dozens injured. Earlier that summer, a massive gust front strike the Bearded Theory Festival in Devonshire in the United Kindom. There were injured when the high winds lifted the roof off the main stage. The same story happened at the 2008 Rocklahoma festival in Tulsa, Okla., the 1997 Thunder Country USA event in north Wisconsin, and more.

After those disasters, we are trying to ask what's going on and why are so many concert outdoor stages collapsing. Much attention focused on the lack of regulation and knowledge, concerning temporary stages erection and maintenance. The more important lessons that people could learn from it is what we could do prior to the disasters. For engineers and design firms, structures should not be limited to design by codes and standards. They have to perform as much Standard of Care as they can. For organizers, it's an opportunity to learn how much preparedness will be needed and how to make decisions regarding the balance between life's and money. As PLASA's Ruling says, "Although you lose money when you don't do the show, you wind up losing a lot more...with a stage blown over, and you're stuck in litigation for years and people are dead"


 * Conclusion **

As the information discussed in this Wiki, it's determined that the disaster happened at Indiana State Fair on August 13, 2011. was caused by the insufficient later force resisting system (LFRS) of the structure as well as the lack of preparedness and management. The collapse was caused by four major structural problems: the guy line system doesn't have adequate capacity to resist the wind loads at the date of the event; the Jersey barriers installed at ISF Structure provided insufficient resistance against the wind loads by the friction; the pin plate failed at the bottom tube due to it's limited bending capacity; and the slender truss columns' capacities were reducing by combination of the axial load and the bending.