San Diego Fire-Rescue Chula Vista
Imperial Beach firefighters work on a mulch fire in Palm City Sunday. Photo credit: OnScene.TV

A fire of unknown causes broke out in a huge mulch pile, the size of a city block, early Sunday in Palm City.

The blaze in the pile, which reached up to 40 feet high, took place at a nursery on Hollister Street at about 9:45 a.m., according to OnScene.TV.

Three fire agencies responded – from San Diego, Chula Vista and Imperial Beach. The effort included four engine companies and two water tenders.

Though the cause has yet to be determined, San Diego Battalion Chief Alfredo Duron told OnScene that he did not expect investigators from the Metro Arson Strike Team to be summoned.

Firefighters planned to extinguish the flames, that at times were “burning pretty heavily,” Duron said, within two hours.

The mulch pile could smolder for days, but the battalion chief added that crews would attempt to “get that deep-seeded smoldering fire as best we can.”

There were no reported injuries.