The San Bernardino County Sheriff's Department received a request to assist the Fire Department in the 22900 block of Redwood Way in the Valley of Enchantment area.
The deputies learned that the man living in the house had guns and explosives inside.
Deputies watched as a man left the home through a back door. They ordered him to stop and show his hands, according to a sheriff's news release.
The release said the man continued to approach the deputies, and when he reached into his waistband, the deputies shot him.
Paramedics pronounced the man dead.
"Sheriff's homicide investigators are conducting the investigation," said sheriff's spokeswoman Cindy Bachman. "Sheriff's bomb/arson investigators are assisting with a safety check of the residence and arson investigation."
The Sheriff's Department did not say if deputies found a weapon on the man.
Anyone with information can contact Detective Eddie Bachman or Sgt. John Gaffney at 909-387-3589. Callers who wish to remain anonymous can call WeTip at 800-782-7463 or www.wetip.com.