Firefighters put out a two-alarm residential fire in unincorporated San Leandro this morning, an Alameda County fire dispatcher said.

Battalion Chief Ronnie Oatis said the fire was ignited by a mattress placed too close to a wall heater.

The fire was reported at 7:10 a.m. at a four-unit residence in the 15900 block of Marcella Street, nearby Hillside Elementary School.

When firefighters arrived at the scene, heavy smoke was coming out from the first and second floor of the building.

A mother and four children were reportedly inside the building when fire crews arrived Oatis said. The woman dropped the youngest child out of the second story of the burning building to be safely caught by fire crews. She then jumped out afterwards.

Firefighters rescued a 4 and 6 year old while the fourth child escaped on its own. The family was taken to a nearby hospital for smoke inhalation no one suffered any life-threatening injuries Oatis said.

The Oakland Tribune reports that the fire displaced a dozen residents but caused no serious injuries.

Firefighters had the blaze under control by 7:30 a.m., the dispatcher said.

Bay City News contributed to this report.