Fire investigators are trying to figure out what started a fire in an apartment building near El Cajon.

The fire broke out just before 11 a.m. in a building on the 1300 block of Diamond Lane.

Two people were inside the lower unit, where flames broke out. They were able to get out safely without any injuries.

Fire crews worked quickly to keep the flames from spreading.

The Red Cross is helping the people who were displaced by the fire.