Video: Bay Area groundskeeper rocked by powerful firework while mowing lawn

Bay Area groundskeeper injured by illegal firework

A groundkeeper from Petaluma was injured when an illegal firework went off.

PETALUMA, Calif. - Petaluma police released a video in the hopes of preventing similar problems.

A school groundskeeper from Casa Grande High School was suddenly rocked by a firework that had been on the grass while he was moving the lawn on June 20 about 10 a.m..

The firework triggered a powerful explosion, but the groundkeeper was not seriously hurt, police said.

The Sonoma County Sheriff's bomb squad responded.

It's unclear where the firework came from.