Student describes explosion inside Derry Area High School chemistry lab

DERRY, Pa. — A Derry Area High School chemistry teacher was airlifted to a hospital late Wednesday morning after suffering burn injuries in a chemistry lab explosion.

School officials said the incident happened just before noon Wednesday in a chemistry lab at the district's high school.

Brian Clawson, a chemistry teacher, was flown to UPMC Mercy Hospital with burns on his face and hands.

Clawson had mixed potassium nitrate with table sugar in a skillet-like container, said Paul Barnhart, a 16-year-old junior who was in the class. Clawson was stirring the mixture with a rod when it exploded.

“It looked pretty bad. It was on his face. It was third-degree. It looked pretty bad,” Barnhart said.

According to Barnhart, there were nine other students in the classroom at the time Clawson was running the experiment.

“I could hear everybody screaming and everybody frantically running around,” Barnhart said.

Barnhart suffered a burn on his foot and he said a female student tripped after the explosion.

Channel 11’s Julie Fine talked to Clawson’s father, Jim Clawson, Wednesday night after he visited his son at the hospital.

“He has burns to his face and arms, but he’s OK,” Jim Clawson said.

According to Jim Clawson, his son told him he’s done the same experiment many times in the past and he doesn’t know what went wrong.

Clawson also said his son was quick to ask about the condition of his students.

“He was real worried about his student,” Clawson said. “He wanted to know if they were all OK. As far as we know, there were no injuries to the students.”

Students who were near the classroom at the time of the explosion told Channel 11’s Alan Jennings that the explosion “sounded like a desk slamming against the wall.”

“They were rushing and everyone was saying, ‘Call 911,’” Ashley Sokolsky, who was in the classroom across the hall, said. “They were frantic and saying there was an explosion.”

The students were evacuated and the school was placed on lockdown until firefighters and other emergency crews could confirm it was safe to resume classes.

Click here to see a YouTube video of a reaction of potassium nitrate and table sugar.

WPXI