The half-acre fire that broke out Monday night in the northern part of the Air Force Academy was 50 percent contained by 11 a.m. Tuesday, according to an academy spokesman.

Meade Warthen, USAFA public affairs spokesman, said there is a line around the fire at Jack's Valley and there was no threat of the blaze spreading further.

Fire crews from the Air Force Academy, Tri-Lakes, El Paso County and the U.S. Forest Service worked together to attack the fire, Warthen said.

"There is water on the fire and it is 50 percent contained," Warthen said. "There are still hot spots and some smoke visible, but no flames."

The cause for the fire was unknown, but no injuries or damaged structures were reported.

All fire crews will remain on site until the blaze is extinguished completely, according to academy officials.