A fire that broke out at a Santa Monica apartment building April 13, temporarily displacing residents, was apparently caused by a lit cigarette in one of the units, fire officials said.

Six Santa Monica Fire Department engines, with the assistance of a Los Angeles City Fire Department engine, were called to the 1300 block of Second Street in Santa Monica shortly after 5 p.m. regarding a structure fire.

Fire department spokesman Capt. Judah Mitchell said one of the tenants, who requires the use of an oxygen tank, fell asleep while he was smoking. When the man woke up he saw that the tubing on the tank had caught fire and after he was unable to put the flame out, he left his first-floor unit and called 911, Mitchell said.

Many residents had evacuated the pre-1933 building by the time firefighters arrived and others were assisted out of windows and fire escapes with the use of ladders, Mitchell said. A couple of the tenants were treated for minor smoke inhalation at the scene but no one was transported to the hospital, he said.

Firefighters were able to contain the blaze to the first-floor unit and extinguished the fire in approximately 15 minutes, Mitchell said. A portion of the building received smoke damage but the estimated loss has not been determined, he said.

Volunteers from the Santa Monica and Los Angeles chapters of the American Red Cross provided blankets, comfort kits, water and snacks to approximately 25 tenants who were on the premises when the fire broke at the multistory building.

Displaced persons, including some with medical issues, elderly and/or disabled, were temporarily placed in a Santa Monica Big Blue Bus parked on Arizona Avenue to get them out of the damp and cold wind, a Red Cross spokesperson said.

The city Building and Safety Department “yellow-tagged” the building due to electrical issues and other safety concerns, temporarily limiting access only for emergency situations.

Tenants were escorted in and out of the structure by firefighters to retrieve medicine and personal essentials before they were transported to an emergency shelter set up by the American Red Cross, the organization spokesman said.