Tulsa, OK – People forced out of a downtown apartment complex were allowed home after a carbon monoxide leak initally caused an evacuation.

The building was without power until Thursday afternoon. It happened at the Hewgley Terrace apartments near 7th and South Lawton.

Fire and hazmat crews believe the power outage may have caused the carbon monoxide leak. They ventilated the building, and allowed people to return home.

FOX23 found out the first indication that something was wrong came when an alarm went off in the first floor boiler room.

When fire crews arrived on scene they detected carbon monoxide and evacuated the building.