Two Temple University students were seriously injured after falling four stories while trying to pose for a selfie at a rooftop party over the weekend, according to reports.

The female students had been drinking on a rooftop with friends about 2 a.m. Saturday in North Philadelphia when they fell over a parapet barrier and plummeted to an alleyway four stories below, ABC News reported.

The cause of the accident is not yet known.

Temple police are investigating along with Philadelphia police.

The victims were not identified. One is in critical but stable condition with multiple injuries, while the other woman suffered leg and ankle injuries.

Other students familiar with the building described the rooftop deck as unsafe.

“There’s not enough room blocking you from falling off,” said Temple University student Arnav Johri, according to ABC. “So if you’re drinking and you run right into it, it’s really easy to slip right off because it only comes to like a little halfway between your knee and hip.”

In 2013, another Temple University student died after after tripping over a 10-inch ledge and falling off a roof not far from the location of Saturday’s accident.