AFP, JAKARTA:  Indonesian investigators were sifting through the rubble at Jakarta’s stock exchange complex yesterday as they looked for clues to what caused a walkway collapse that left scores injured, including dozens of visiting university students.

A mezzanine floor at the tower in the city’s business district crashed to the ground shortly before lunchtime Monday, injuring 73 people, police said. There were no deaths.

Dramatic CCTV footage showed a group of about 40 students on a balcony section plunge as the floor gave way with a cascade of glass, metal and other material showering the ground floor where several other people were walking.

National police spokesman Setyo Wasisto said the investigation team was hoping to gather crucial evidence by the end of Tuesday, though the results of their probe will not be known for several weeks.

Investigators will look at building material quality and the site’s structural integrity, said Mushanif Mukti, a top official at the Association of Construction Safety and Health Experts.

“It needs to be examined to see whether it is structural fatigue or it’s a weight issue,” he said.

Jakarta’s governor Anies Baswedan has ordered an inspection of the complex, which was last checked in May last year.

Officials have described the collapse as an accident and not the result of an explosion—the tower was bombed by Islamist militants in 2000, killing 10 people.

“If they (investigators) are done today, everything can be cleaned up and the ... scene can be re-opened,” Wasisto said.