The Honolulu Fire Department determined a work pickup truck that broke down in a grassy area caused the massive brush fire in Mokuleia that so far has scorched about 400 acres.

Firefighters responded to a three-acre wildfire near 67-172 Farrington Highway at about 11 a.m. Wednesday. The fire quickly spread to a 400 acres by late afternoon. Honolulu Fire Spokesman Capt. David Jenkins said the Department of Land and Natural Resources, Honolulu police and the U.S. Army assisted in battling the wildfire with ground crews and helicopters.

A group of firefighters remained at the scene overnight until additional firefighters, state forestry crews along with several helicopters returned to the site today to contain the fire. Windy conditions caused the fire to grow 45o acres as of 12:15 p.m.

Jenkins said the blaze is 50 percent contained. The wildfire continues to burn in inaccessible areas in the upper slopes and has encroached forested areas.

No injuries or property damage were reported.

Jenkins said the point of origin of the wildfire was a mango tree grove. “Operators of a pickup truck which broke down stated that the fire began from their truck. They witnessed the fire start at that point.”

It’s unclear at this time exactly what happened from the broken down truck that sparked the fire. Jenkins said the vehicle was consumed in the blaze. No injuries were reported.