L.A. County sheriff's deputies from the Lakewood Station received a report of a disturbance at a business on the 16400 block of Woodruff Avenue in Bellflower at about 1:30 a.m.
A 57-year-old man confronted arriving deputies at the location. He was incoherent and foaming at the mouth, according to the sheriff's department.
A physical altercation followed, and the suspect punched one deputy in the head and pushed the other deputy into a water fountain, according to the department.
Deputies tried to use a Taser to subdue the man, but it had no effect, the department said.
During the fight, the suspect reached for one deputy's holstered firearm. The other deputy shot the suspect.
The suspect was pronounced dead at the scene.
The deputy who was punched was hospitalized, treated and released. The other deputy was treated for minor injuries at the scene, the department said.