PHOENIX — A Maricopa County sheriff's deputy has been shot and killed while answering a burglary call in the north Phoenix community of Anthem.

Sheriff Joe Arpaio said 50-year-old deputy William Coleman and his partner found a suspect in a van at a medical building at about 4 a.m. Sunday.

The 40-year-old man got out of the van and opened fire with an assault rifle, striking Coleman under his bullet-proof vest. The deputy was taken to a hospital, but doctors could not save him.

Other deputies shot the suspect to death. Investigators are trying to determine why he opened fire, Arpaio said.

Coleman was a 20-year veteran. He leaves a wife and two young children, ages 4 and 7. Arpaio says he also has grown children in another state.