Palo Alto police and firefighters responded to a small explosion in a Palo Alto apartment complex Tuesday night. The building was evacuated and traffic was halted in the surrounding area due to toxic gas, police said.
The Palo Alto Fire Department located the source of the odor in a pool supply area beneath a stairwell. Firefighters found a five-gallon bucket containing a chlorine-based substance that was violently "off gassing," police said.
The substance was removed from the building and firefighters were able to stop the hazardous fumes. Residents were allowed to return to their apartments at around 9:30 p.m.
Seven residents and one Palo Alto firefighter were evaluated for exposure to the substance and were treated on the scene. The Red Cross assisted one family that was unable to return to their residence.
Firefighters stored the substance for further evaluation by the Bureau of Alcohol, Tobacco and Firearms. Investigators do not yet know if the explosion was accidental or intentional.