Emergency crews responded to a collision in City Heights involving a San Diego Fire-Rescue engine and a vehicle.
The collision was reported shortly after 10:20 a.m. in the 3900 block of University Avenue, near 40th Street.
10News learned the fire engine was responding to an emergency call when the crash occurred.
At least two people were taken to the hospital with injuries of unknown severity, authorities said.
The crash left University Ave. completely blocked at the site of the wreck, in both directions. Police advised motorists to avoid the area until further notice.
The southbound Interstate 15 off-ramp to University Avenue was also closed.