The Palo Alto Fire Department and Palo Alto High School administration are investigating why a classroom fire alarm failed to go off after a chemistry demonstration yesterday ignited a fire that injured a teacher.

Chemistry teacher Silja Paymer, who conducted the demonstration, received superficial first- and second-degree burns but was released from an emergency burn unit shortly after being transported to the hospital. She told The Paly Voice in an email last evening that she is now resting at home and will return to teaching after spring break.

According to witness sophomore Jessica Wong, an explosion occurred during 3rd Period while Paymer was finishing up a gas law property demonstration with flammable liquid methane. Some backpacks and papers were damaged, but no students were hospitalized after the fire.

PAFD Battalion Chief Kevin McNally said that though PAFD is in the process of investigating the matter, there may not have been enough smoke in the room to trigger the fire alarm.

“It was not a sustained fire,” McNally said. “I can speculate that the alarm didn’t go off because most of them are smoke detectors, not flame detectors. Unless there’s enough smoke produced to actually set the alarm off, it won’t go off.”

Wong noted her concern about the apparent fire alarm malfunction.

“I was pretty shocked that there had been a literal fiery explosion and the alarm didn’t even go off,” Wong said. “There was definitely smoke in the room.”

According to Wong, Paymer immediately used the emergency shower, a feature that is installed in every science classroom, to put out the flames on her body, and students poured water onto burning items in the room.

“It [the fire extinguisher] didn’t get used,” Wong said. “I think it’s because all the fires were so small and spread out.”

Sophomore Jordan Quigley, who was also in the classroom at the time of the fire, said that Paymer told a group of students to get help from science teacher Ron Bowditch in the room next door. Bowditch then called the paramedics and school personnel.

“Paymer was pretty calm for what had happened,” Quigley said.

According to sophomore Aman Mittal, another witness to the explosion, the methane used in the experiment was supposed to spark a flame to propel a plastic container backward. Mittal noted that the experiment failed multiple times and suddenly erupted into flames on the final attempt.

“She [Paymer] was working with methane in an empty milk carton to make a reaction happen, but it wouldn’t work,” Mittal said. “So she kept trying, and I guess all the methane from the previous tries reacted, as in caught fire, and the entire front of the room burst into flames for a split second.”

Wong said that the students were grateful that Paymer reacted quickly to the incident.

“We’re so lucky that it [the whole classroom] didn’t catch on fire and [that] no one else got hurt – not even people sitting in the front row,” Wong said.