TUCSON, Ariz. -- A Pima County Sheriff's Department helicopter crashed on the side of a rugged mountain Monday, killing one person and injuring three others.
Authorities say one of the survivors is hospitalized in critical condition and the other two are in serious condition. Their names haven't been released and sheriff's officials won't immediately say if all four people aboard the copter were department employees.
Authorities say the Hughes 500 helicopter went down northwest of Tucson around 11 a.m. as the four-person crew was scouting an area in the Ironwood National Forest for possible locations for radio communications towers.
Federal Aviation Administration officials say the cause of the crash isn't immediately known.