Officials have confirmed the fatalities happened when the driver crashed into nine pedestrians in a tunnel near San Diego City College.
“Our crews found, obviously, a tragic incident under the bridge,” said SDFD Chief Colin Stowell.
The driver, a 71-year-old male, was arrested at the scene of the incident.
SDPD Chief David Nisleit said the driver of the Volvo car was cooperating with police and being investigated for suspicion of driving while impaired.
The San Diego Fire-Rescue Department said first-responders arrived on the scene of the incident, which is in a tunnel that leads to the college, within five minutes.
“The way he was driving down the sidewalk, it was like he didn’t take his foot off the gas until he got to the other side of the street,” witness Ronnie Williams told KGTV.
“I’m like whoa! Is this guy ever gonna stop?”
Mr Williams said that the driver got out fo the car and “casually walked away” from the scene.
The tunnel near the college is often used as shelter by homeless people and the sidewalk is regularly filled with tents, according to the San Diego Union-Tribune.