NEW YORK (CBSNewYork) -Two teen girls suffered third degree burns when an experiment they were working on in chemistry class caught fire in the Bronx Friday.

It happened at around 1:40 p.m. at Morris High School on Boston Road in the Morrisania section.

According to officials with the FDNY, the students were making a carbon sugar snake. The experiment involves using alcohol, and while the experiment was underway some vapor escaped and made contact with the flame that was being used to create the snake, officials said. Flames shot across the table, causing burns to the face, hands and hair of two girls, 15 and 17.

“From what I saw her arm was on fire, her sleeve,” one student said. “When I saw her running down the hall that’s what I saw.”

Investigators say a teacher was in the room at the time, but it’s not immediately clear how a chemical was able to get close enough to a flame for this to happen.

After the ordeal students were allowed to gather their belongings and go home for the day. Even though their classmates are expected to recover, it has many feeling shaken.

“FDNY and EMS immediately responded to this serious incident, and students are in stable condition being treated for non-life threatening injuries,” said Miranda Barbot of the Department of Education. “The safety of our students is our top priority, and FDNY is conducting a thorough investigation. The lab will be out of use until it is completed.”