OCEANSIDE, Calif. — One person was injured and 13 displaced after a fire broke out in an Oceanside home Saturday afternoon, fire officials said.

Around 12:05 p.m., a concerned passerby reported the fire at the home in the 2900 block of Thunder Drive. A total of 20 personnel were dispatched by the Oceanside Fire Department, arriving on the scene around 12:11 p.m.

Fire officials say the flames initially started on the exterior of the house before spreading into the attic and one bedroom.

The first two crews to get to the fire did so within seconds of each other, the department said. One began “an aggressive exterior attack” with hoses while the second unit conducted a search for occupants and worked to extinguish the fire from inside.

However, all residents had safely evacuated the premises, according to OPD. One of the residents was treated on-scene for smoke-related injuries, but they did not require hospitalization.

Due to heavy smoke from the attic vents, fire personnel also had to cut a large opening in the roof with chainsaws. According to OPD, the “tactical ventilation” helped put out the flames and prevent further spread.

All 13 residents who lived on the property were displaced as a result of the incident. The Red Cross is currently providing support to those impacted.

An investigation into the cause of the fire remains ongoing at this time.

In a release on the incident, fire officials stressed “the critical role (residents) play in emergency situations — your alertness and rapid calls to 911 save lives and properties.”