DERRY, Pa. (AP) — Students were evacuated from a western Pennsylvania high school after a science teacher was hurt by a chemical reaction during class.

Officials with the Derry Area School District say the incident happened late Wednesday morning in a chemistry lab at the school, about 40 miles east of Pittsburgh.

The teacher was taken by ambulance to a hospital for treatment of burns to his face and neck. The school hasn't released details of his condition but the man's father tells local media that his son is "doing well."

One student also suffered minor burns but was released to his parents, while another was injured when she fell while leaving the scene.

Authorities say they're still investigating what went wrong with the experiment.