NORTH PLATTE, Neb. (AP) — Authorities are investigating after a grass fire burned for nearly two hours and threatened homes south of Lake Maloney in North Platte.

Battalion Chief Jason Trimble of the North Platte Fire Department says he believes the fire had spread 100 acres by the time he arrived to the scene Thursday. Assistance was requested from several other fire departments, and Trimble says local farmers helped combat the blaze as well.

Trimble says he doesn’t know what caused the fire.