WINDHAM, Maine — A brush fire broke out Monday, burning about 100 square yards before firefighters could contain it.

Families in the Cornerbrook addition, off Route 302 in Windham, were the first to spot the smoke high on a ridge behind their homes. For firefighters, fighting a wildfire on a steep ridge 70 feet high wasn’t easy. A second group of firefighters fought the brush fire from the other side of the ridge.

“The terrain is extremely difficult to get hoses up through,” Windham Fire Chief Brent Libby said. “The guys are in all their gear — chainsaws, tools — so they’re working pretty hard to make sure that it stays pretty contained.”

The fire burned down the ridge toward homes when the wind changed direction.

The cause of the fire remains under investigation. Maine Forest Ranger Brad Bucknell said he’s “still looking into it. I need to talk to some more homeowners in the development here.

“There’s a lot of camping, a lot of backyard barbecues,” Bucknell said of Memorial Day weekend celebrations. “Where fireworks are legal in Maine, that’s another potential fire source. We just ask everybody to be vigilant.”