No officers were hurt.
Authorities said two officers tried to stop the man as he was walking on the north side of the 215 Freeway overpass near 5th Street.
For unknown reasons, the man began shooting as he ran away from officers. Police fired back, striking the man several times.
The man was taken to a hospital, where he later died.
Authorities said the situation could have been a lot worse.
"There could have been a lot of pedestrians, vehicle traffic in the area," said San Bernardino police Capt. Gwendolyn Waters. "It helps it was a Saturday at 7:30 a.m. You can have a lot of traffic out on these streets, but since it was a Saturday it was little less crowded."