DINWIDDIE COUNTY, Va. (WRIC) — Dinwiddie County Public Schools, the Dinwiddie County Fire Department and the Sheriff’s Office held a joint press conference about the fire that took place last week at Dinwiddie High School that injured several people.

According to Dinwiddie County Public Schools, an “incident” in a chemistry class on the morning of Wednesday, Oct. 12 caused the school to be evacuated and closed early.

Three students and a teacher were taken to hospitals for treatment, a fourth student was treated for injuries at the scene. According to Dinwiddie County Public School Superintendent Dr. Kari Weston, two of the students have been released and are at home under a doctor’s care. However, but the third is expected to be in the hospital “for some time.” Dr. Weston said the students have a long recovery ahead of them.

According to Dinwiddie Fire Chief Dennis Hale, the fire was caused by a flammable liquid demonstration in a chemistry classroom. There were 19 students in the classroom at the time.

Methanol was put in an open-top beaker with water and ignited using a smoldering wooden splint. Trying the demonstration a second time, the teacher of the class was in the process of adding more methanol to the beaker from a container when the methanol vapor in the bottle’s opening caused a phenomenon called “flame jetting.”

This caused a large amount of the methanol in the bottle to ignite and the fire traveled about ten feet across the front of the classroom, hitting a whiteboard and igniting pieces of paper posted on the wall. The four students injured were in the direct path of the fire as it traveled across the room.

The ignition source is believed to have been the methanol that was still burning in the beaker from the previous demonstration while more methanol was being poured in. The wooden splint used to ignite the previous demonstration was also still located in the vicinity of the beaker, according to Dinwiddie Fire.

The ignition caused a large noise, but it is not believed that any explosion took place in the classroom, according to the Dinwiddie Fire Department.

Weston said the teacher is on leave until further notice, but would not elaborate on the circumstances.

Dinwiddie County Public Schools additionally released a statement on Wednesday, Oct. 17 that the school district is conducting an internal investigation which will include a review of school safety protocol.