Nearly 80 people were injured after a mezzanine floor at the Indonesia Stock Exchange in Jakarta collapsed on Monday. National Police Spokesperson Inspector General Setyo Wasisto said most of the injured were college students on a study tour from Indonesia’s Sumatra island, AP reported.

The casualties stand at 77, according to figures released by five hospitals.

Footage from security cameras showed a group of people plunging several feet to the ground as the balcony overlooking the main lobby of the exchange collapsed. The police ruled out explosives as the cause of the collapse.

Indonesia Stock Exchange President Director Tito Sulistio said the exchange will pay to treat the injured.

Authorities completed evacuating the building, and afternoon trading resumed after the chaos on schedule.

The building is part of a complex that Islamist militants targeted with a suicide bombing in September 2000.