City Hall failed to meet security rules when constructing Madrid Arena

The investigation commission set up by Madrid City Hall to investigate the events leading up to the Halloween party disaster in the capital, which claimed the lives of five young women, was expected to close on Monday after hearing the testimony of security councilor Antonio de Guindos and his number two, Fátima Núñez. Urban development councilor Paz González, deputy mayor Miguel Ángel Villanueva and economy delegate Pedro Calvo, who stepped down after being named a suspect in the criminal investigation into the tragedy, were also due to appear.

Both the Socialist leader in Madrid, Jaime Lissavetsky, and UPyD leader David Ortega, were due to quiz González over a 2010 report by her department laying out the security deficiencies at Madrid Arena, and why nothing had been done to remedy them. Lissavetsky believes that Calvo's resignation is insufficient and has pointed the finger at Madrid Mayor Ana Botella, of the Popular Party.

Madrid Arena was built with excessive haste and without complying with security regulations - to bring it in line with legal requirements was considered too expensive, and was therefore not done. City Hall did not want to sell it but continued to hire it out for an increasing range of events, including huge parties for which it was not suitable. On the night of the tragedy, the temporary stage that was set up was blocking some of the venue's exit points. City Hall authorized the event with a dance floor capacity of 3,680. The event organizer allegedly sold thousands of tickets, well in excess of Madrid Arena's official capacity of 10,600.

Madrid Arena was built on the site of the old Rockódromo open-air site, and was originally earmarked in 2001 as the 2012 Olympic Games tennis venue. It was remodeled with considerable haste to host the ATP Tour Masters tournament. When Alberto Ruiz-Gallardón became mayor that year, he expanded its budget to 16 million euros. In 2004, the site hosted an opera.

On the night of the tragedy, five of eight exits of the arena were blocked

Almost seven years later, in March 2010, City Hall technicians compiled a report on the venue's security deficiencies. Among these were: "It is not easy for fire crews to gain access;" "Access is only possible in an area of approximately one-fifth of the façade. The other four-fifths are closed and inaccessible because of maximum height restrictions and floor resistance." Because of these faults, Madrid Arena failed to comply with the Technical Building Code.

City Hall wanted to sell the building, for which it needed licensing approval. It had been trying to gain this since 2007 without success, precisely because of these deficiencies. It decided to keep hiring it out instead.

Nor was Madrid Arena ever designed for huge dance parties like the Thriller Music Park event, where the tragedy happened. The same technicians gave the site the green light for sports events, fairs and concerts. In the case of the latter, the capacity was set at 8,649 seated attendees. If it were to host a fair, an emergency would see 925 people evacuating through seven three-meter wide exit corridors and a nine-meter-long emergency passage. The security study concluded that it would take two-and-a-half minutes to clear Madrid Arena. In the case of a party such as that held on Halloween, the emergency exits would have to withstand the evacuation of 3,600 people, something that the building plan did not take into account.

In the early hours of November 1 that amount of people was on the main dance floor of the venue. The stage was allowed to block one of the exit routes. The organizers blocked a further two to install platforms for dancers. At one point during the party, another was blocked off. But the main cause of the tragedy was when the larger emergency exit was opened - not to allow people out but in. Therefore, people wishing to leave the dance floor had just four narrow exit corridors to use. In all, almost 17,000 people found their way into the event, many of them making for the main dance floor when the star turn of the night, DJ Steve Aoki, began his set at 3am.