On Wednesday, May 4, 2005 at 8:41 AM PDT, eight Companies of Los Angeles Firefighters, ten LAFD Rescue Ambulances, one LAFD Hazardous Materials Task Force, one LAFD Helicopter, three EMS Battalion Captains and three Chief Officer Command Teams under the direction of Battalion Chief Patrick Butler responded to a Hazardous Materials Investigation at 6635 Tobias Avenue in Van Nuys.

Firefighters arrived quickly at St. Elisabeth Parish School and were directed to a two-story school building, where according to staff, a male custodian cleaning debris in an interior first floor hallway discovered an unknown product in powder form, and soon thereafter complained of minor eye and respiratory irritation.

Early reports that this substance was related to school vandalism proved to be false.

Firefighters subsequently encountered nine adult staff members with identical complaints. Following a medical evaluation by Firefighter/Paramedics in fresh air, their symptoms subsided. All were released at the scene without acute need for treatment or transportation.

A total of 290 students in the Kindergarten through 8th grade facility were offered comfort and reassurance while being calmly sheltered in place. The students and other faculty members expressed no malaise, and displayed no signs of distress.

LAFD Hazardous Materials experts thoroughly evaluated the scene and identified the product in question to be "sodium bicarbonate".

It was later determined to have been remnant of a previously donated child's chemistry set discarded in or near a school waste can. County of Los Angeles Health HazMat Division workers will further investigate the incident.