Overcrowding and Crowd Control

Several studies have highlighted that despite venue capacities being completely full, further crowd members still tried to gain access, either due to overselling of tickets or by people turning up just before or after the start of the event. An adequate ticketing system and public address measures to inform crowds of no further access to an event once capacity is reached is essential.

Training of stewards and security staff in crowd control should be implemented before an event in an effort to improve crowd safety and avoid panic should overcrowding occur. During a football match in Ellis Park South Africa, tear gas was thrown in to a crowd by event security in an effort to disperse intense overcrowding. This unfortunately served to incite panic and cause stampede [5] .

Overcrowding has been linked to the collapse of a temporary stand at a football match in Corsica [6] , while in the UK, the Hillsborough disaster in April 1989 led to a landmark report by Lord Justice Taylor, to change all football stadia in the UK to all-seater venues, improving crowd safety and control as well as removing pitch-side barriers and improving medical facilities on-site [7] .

Two cases at music events have stressed the need to provide ‘mosh’ pit safety. Since ‘moshing is a dance in which participants push or slam into each other in enclosed spaces, primarily during live music events, mosh pit crowd safety guidelines have been implemented, which include isolating the area from the main audience, provision of nearby first aid, and protocols to stop artists performing should crushing develop [8] .

Event Access Points

One key structural element to an event venue is the provision of adequate site access, not only for participants but also for emergency medical services.

The Ibrox stadium disaster in 1971 [9] involved fans leaving the stadium getting caught up with fans entering the stadium at the same time, leading to crush and stampede when all fans heard a goal being scored. Further episodes of crowd convergence have occurred at a stampede causing the death of 1,426 during the Hajj in 1990 where pilgrims spontaneously rushed to leave Mecca via one exit [10] , and during the Love Parade in Germany 2010 where overcrowding led to devastating consequences in a tunnel providing the only means of entrance and exit to fans of a music festival [11] [12] . To address this, many mass gathering events now have access points solely for entrance or exit at the site, promoting a unidirectional flow of crowd members and dramatically reducing the risk of crowd convergence.

Emergency medical services unable to access event sites was found to be a major factor in the prolonged response time to the Ramstein air show disaster, where members of an Italian Air Force display team collided and crashed to the ground [13] . While at a traditional festival in Cambodia, no access routes were available for emergency medical services to a stampede, severely hindering the medical response [14] . It is suggested the planning for future events includes provision of easy, unobstructed access for EMS vehicles.

Fire Safety Measures

Fire safety has become an increasing part of emergency planning, however several lessons can still be identified. The stardust fire in Dublin 1981 was thought to have been deliberately started from the ignition of newspapers under flammable seats resulting in 48 deaths and 128 injuries [15] .The Bradford City Stadium Disaster is thought to have started by a dropped match or cigarette falling through floorboards to rubbish below [16] . 441 deaths occurred at an Indian wedding due to a synthetic cloth tent catching fire in a large area with no means of emergency exit [17] , and 375 attendees were caught in a nightclub fire in Gothenburg, Sweden when the venue was only supposed to hold 150 with the fire starting in front of the emergency exit [18] . Only one of three emergency exits were available during a nightclub fire in Volendam, Netherlands [19] .

From the five events reviewed it appears that all fire disasters had similar attributes that emergency planners should consider when planning for a mass gathering:

Several emergency exits should be made available at any planned event.

Medical Preparedness

Provision of on-site physician-level medical care at mass gatherings has been shown to significantly reduce the number of patients requiring transport to hospital and therefore reducing the impact on the local ambulance services [20] . The majority of non-disaster injuries and medical complaints at a mass gathering can be effectively treated on scene, which reduces the number of hospital referrals and patient presentation rates to hospital [21] .

Following the Hillsborough Stadium disaster 1989, Lord Justice Taylor [22] made suggestions to improve on-site medical care (Box 1):

On-site medical care has also dramatically improved following several stampedes occurring during the annual Islamic pilgrimage of the Hajj [10] . The most notable event in 2006 resulted in 346 deaths at a bottleneck area in the Mina Valley. The provision of specially equipped medical care facilities, helipads, electronic surveillance, shading and cooling mists have helped to reduce crowd morbidity and mortality [10] . Local hospitals should also be involved with emergency planning in preparation for potential mass gathering disasters. Madzimabuto [23] , in a review of a stampede at a football match identified the following hospital preparedness deficiencies identified as:

Emergency department only first aware when injured arrived

It is suggested that when planning for a mass gathering event, local hospitals should be involved in healthcare provision not only on-site but also for their own planning of mass casualty events allowing for potential occurrence of disaster.

For mass gatherings on larger scale such as Olympic Games, an assessment of terrorism risk assessment might be necessary, with further medical provisions available during these planned events. For example Feliciano et al [24] reported that there was extensive pre-Olympics preparation (Box) at the regional Level 1 trauma centre before the Atlanta Games in 1996. In particular the pre-hospital training (point 4, box 2) resulted in an excellent hospital-wide response to the multi-casualty event following the explosion of a pipe-bomb in Centennial Park during these 1996 Olympics which resulted in 1 death and 21 injured on scene.

Emergency Response

Many of the case reports highlighted a poor response time for emergency services but it is unknown if each event reviewed had a mass gathering major incident plan available. However, it is necessary to have one in place to co-ordinate fast and effective emergency response, to potentially improve morbidity and mortality.

Poor initial communication with emergency medical services was a key finding in not only the Ramstein air show disaster [13] , but also in stampedes at the Miyun Country bridge disaster in China [25] , the Akashi firework event in Japan [26] and at a religious temple in Uttar Pradesh [27] . These highlighted poor triage of casualties. Indeed in one instance it was triage was initiated approximately 80 minutes after the incident occurred [26] .

It has been suggested that emergency planning has considered that emergency personnel on-site have adequate training and experience in disaster medicine, utilising appropriate triage methods. One analysis of medical care at mass gatherings by Sanders et al [28] suggested:

Basic first aid within 4 minutes

However these suggestions are based on only low patient numbers requiring triage, and arose from low-level evidence and expert judgement, which the authors stressed is in need of further research [28] .

Event preplanning using these principles has been described by [12] in relation to the 2010 Love Parade in Germany when major medical preparations were put in place. They reported on patient care delivery at this mass gathering, where following a stampede, 21 died and over 510 were injured. Once a disaster was called at the site, additional emergency healthcare personnel were brought in, and extra treatment facilities were created to deal with the situation. First-aid posts and emergency treatment and triage stations were set up on site, dealing with a high volume of patients. The formation of trauma teams made it possible to control patient flows appropriately to all hospitals. However, even with such well planned emergency response, adverse consequences occurred which demonstrates again the complexity of planning for such mass gathering events.