This is the terrifying moment the floor caved in at Indonesia’s Stock Exchange on Monday, injuring nearly 80 people.

Security footage shows crowds walking through the building in Jakarta when suddenly the mezzanine floor gives way, sending dozens plummeting to the ground floor.

“There was a rumbling noise but it wasn’t an explosion,” a student named Alfita told Reuters.

“It was like something had fallen, and suddenly the floor we were standing on fell away.”

At least 77 were hurt in the collapse, although no deaths have been reported.

The cause of the collapse is still unknown, but police have ruled out terrorism.