JAKARTA | At least 75 people were injured by the dramatic collapse of a mezzanine on Monday in the building housing the Jakarta Stock Exchange, causing a panic in the heart of the business district, according to Indonesian authorities.

Surveillance camera images show a group of about 40 students on a mezzanine that gives way, throwing these visitors down into a cluster of metal, glass and debris on the ground floor where others people were circulating.

A spokesman for the police said it was an accident and not an explosion. The collapse of this small floor has left 75 injured, told AFP a spokesman for the national police, Setyo Wasisto. Miraculously, no death is to be deplored so far.

Images from Indonesian television show scenes of chaos with wounded evacuated or lying on the ground outside the 32-storey building in the heart of the business district.

“I saw a lot of people bleeding,” said Rizki Noviandi, a student who was competing in the building.

“Many people were transported outside the building and left on the grass outside, until the ambulances arrive,” she added.

The injured, most of them fractured on their arms and legs, were taken to the hospital, said another Jakarta police spokesman, Argo Yuwono.

The lobby of the building was filled with debris and spilled plants near a Starbucks café, when the building was evacuated and bombed in 2000 by Islamist extremists.

At least ten people were killed and dozens wounded by the explosion of a vehicle filled with explosives.

“A big boom” 

Witnesses told how the tragedy happened.

“There was a big boom, so the people inside were immediately running out,” Metro TV reporter Marlia Zein testified on the spot at the time of the incident.

The cause of the accident could not be determined immediately.

“A deterioration of equipment could be the cause” of the tragedy that occurred at midday in this building Sudirman district, whose construction dates from 1995, said a construction expert, Iswandi Imran, to journalists.

“It could be corrosion or something that slowly attacks the strength of the structure until it can no longer support a certain weight. But all this must be investigated, “said the expert.

About 100 police and rescue workers were dispatched to the scene of the accident and the car traffic was suspended for several hours. This event caused huge traffic jams in the already congested city center, aggravated by heavy rains.

Despite the chaos, exchanges continued as usual in the afternoon, said a spokeswoman for the exchange platform, Rheza Andhika.

Shortly after 2 pm (Jakarta time), just two hours after the spectacular accident, the building that had been temporarily closed reopened, with employees returning to their offices. Then, hundreds of curious people continued to flock to the building, the police having a lot to do to prevent them from crossing the security perimeter.

The Jakarta Stock Exchange is housed in a building that also houses the World Bank offices on the 12th floor.