MESA, Ariz. -- A Mesa couple has been forced from its home after a fire ripped through at least half of the two-story structure.

The fire started shortly before 2 p.m. Wednesday.

Charlie Marquis, the homeowner's nephew, arrived at the house to do some work. Marquis noticed smoke billowing out from under the garage door. He went inside the home and into the garage, but when he opened the door, all he saw was black smoke. Marquis screamed for his uncle, who was in the back yard. Both men escaped to the front of the house without getting hurt. No one else was home at the time.

Deputy Chief Mike Dunn of the Mesa Fire Department said it took about 40 firefighters nearly 50 minutes to get the fire under control. Dunn did not immediately have any damage estimates.

Firefighters do not yet know how the fire started. It is believed to have started in the garage. Investigators are focusing on the battery of a golf cart that was parked inside.