UPDATED: Hazmat Unit Evacuates Science Building at Arcadia High

UPDATE: A science experiment involving the accidental ignition of single chemical was what triggered the evacuation of the school's science building and the summoning of Hazmat teams, according to officials with the Arcadia Fire Department. No one was injured.

Students were partaking in an experiment that involved bringing cyclohexane, a chemical used primarily to make nylon and solvents, from a frozen to a liquid state. The chemical, which was in a beaker, overheated too quickly and caused a small fire, said fire department spokeswoman Beth Stogner, who added that the chemical quickly burned itself out and left no residue.

There were also no ill effects to any students or faculty following the fire, Stogner said. There were 30 students in the class. Hazmat units from Burbank and Glendale came to the school and were able to identify the chemical, Stogner said.

Original: Authorities have responded to a hazardous materials situation at Arcadia High School, according to authorities.

The science building at the school has been evacuated as emergency personnel investigate the incident. Specifics on the cause of the evacuation were not immediately available.

A westbound lane on Duarte Road has been shut down and police have set up a command post on the street.

Check back later for more on this breaking story.