The cause of a two-alarm apartment fire on the northwest side is under investigation.

The fire started around 2 a.m. Sunday at the Stone Oak Place apartments in the 12000 block of Interstate 10 near DeZavala Road.

Firefighters said smoke and flames affected a total of eight apartments, four of which were destroyed.

There were no injuries reported.

The complex was able to place people from seven affected units into other apartments on the property.

The Red Cross is also helping residents.

Damage is estimated at $175,000.