LEWISTON — Longley Elementary School students were dismissed Thursday morning after a fire extinguisher accidentally discharged.

Around 10:30 a.m., a portable fire extinguisher in a hall fell off the wall and bit the floor, Superintendent Bill Webster said. The contents discharged, creating “smoke-like conditions and set off the fire alarm.”

Students went across the street to the Androscoggin Bank Colisee.

Fire and rescue units rushed to the school and inspected the building.

All students are safe, “the building is safe,” Webster said. “There’s one section of the building that is not usable until we get professional cleaners in tonight. Also student clothing and backpacks need to be cleaned.”

Parents were called to pick up students, Webster said.

Longley Principal Kristie Clark said students practice fire drills and when the alarm went off, everyone left the building in a calm and orderly manner.

“I couldn’t be prouder of the students,” she said.

Lewiston fire Chief Paul LeClair said the pressurized 10-pound extinguisher was full of dry powder, “so when it went off, it made a mess.”

The sprinklers did not go off because there was no heat build-up, LeClair said.

It’s unclear why the extinguisher fell to the floor and why it discharged.

“The pin didn’t come out,” Webster said. “It shouldn’t have discharged.” 

The school has been cleaned up and will be open on Friday, he said.

Fire extinguisher malfunction leads to temporary Longley evacuation. Students are back in gym awaiting parent pickup. pic.twitter.com/PQZ8d8KUXh

— Bill Webster (@LewistonSuper) December 18, 2014