INDIANAPOLIS -- Four people, including a firefighter, were hurt during an early-morning fire at an apartment complex in Castleton Sunday.

The blaze began just before 5 a.m. at the Autumn Woods apartments, near 91st Street and Allisonville Road.

Kyle O'Brien, one of the four who was injured, said he made it out alive because of a smoke detector, 6News' Jennifer Carmack reported.

"I woke up at first and thought, 'I don't have to work today. That's not my alarm. It's much more serious,'" O'Brien said. "I ran out into the living room and the wall was on fire."

O'Brien and his roommate made it out the door. His girlfriend jumped from a three-story window and broke her ankle.

Firefighters rescued a second woman. Neighbors woke each other up and all got out OK.

The injured firefighter was treated at the scene.

"Having that working smoke detector gave them the opportunity to self-evacuate," said Indianapolis fire Capt. Gregg Harris. "It could have been a lot worse."

Five apartments were destroyed in the blaze. Fire officials said firewalls in the building kept flames from spreading.

The cause of the fire is under investigation. It caused more than $200,000 in damage.