Emergency personnel rescued a 19-year-old New York University student Sunday night after he became trapped in a small space between two buildings.

According to NBC New York, Asher Vongtau had gotten trapped in a space between a dormitory and the parking garage next door that was only 18 inches wide. The student had been stuck in the small space for more than a day before emergency workers came to rescue him.

Vongtau was reported missing by his friends on Saturday after he disappeared when a fire alarm went off.

“I saw him frantically running up the stairs while people were exiting the building because the fire alarm had been pulled,” Colin Chenel told CBS New York.

Vongtau’s location was only found after someone was reviewing the building’s security tapes and saw him in the stairwell. His cell phone was located on the roof of the building and authorities later found him wedged in the small space between the dorm and the garage.

It took emergency workers an hour and a half to rescue Vongtau from the space, reports the New York Daily News. They had to break down a brick wall in order to reach him, and he was conscious when he was rescued.

It is unclear to rescue workers as to how Vongtau fell into the space and how he got stuck at the bottom, though one investigator said that he may have been intoxicated at the time.

After his rescue, Vongtau was taken to the nearby Bellevue Hospital, where he is in serious condition.