A driver plowed through a sidewalk homeless encampment Monday in downtown San Diego, killing three people and injuring six others, authorities said.

Craig Voss, 71, was heading through a tunnel underneath a community college campus when he drove his Volvo station wagon up on the sidewalk shortly after 9 a.m., San Diego Police Chief David Nisleit said.

Voss was arrested at the scene. He faces three counts of vehicular manslaughter, five counts of causing great bodily harm and a felony DUI, Nisleit said, adding that Voss did a field sobriety test by a drug recognition expert. He did not elaborate or identify whether Voss was under the influence of alcohol or another substance. He said additional charges may be coming.

It wasn’t immediately known if Voss had a lawyer who could speak on his behalf.

The deadly crash highlights the inherent risks to the homeless population in California, where their tents and tarps line not only downtown sidewalks but are near ramps where cars accelerate as they enter freeways.

More than 150,000 people are homeless statewide. The number has increased during the coronavirus pandemic that has upended the economy.

Mayor Todd Gloria said most, if not all of the nine people who were struck were homeless.

“They were there because they felt like they had nowhere else to go,” Gloria said. “This crash this morning did not have to be so devastating. Let me state it very clearly, a street is not a home.”

Three people died at the scene. Five of the six others who were injured were taken to hospitals. Two were in critical condition. San Diego Fire Chief Colin Stowell said both were “awake, alert and answering questions.”

The mayor, who took office in December, said the encampment had been there awhile and more people might have been drawn to the tunnel under the San Diego City College campus because the cement overpass provided cover on a rainy day.

“For whatever reason, (the driver) veered to the right, went up on the sidewalk, struck multiple pedestrians there and then came back on to the roadway,” Nisleit said. He offered “my deepest condolences” to the families of those who died.

Multiple ambulances responded to the scene near City College, where on a typical weekday morning it is a busy area with students walking by, but classes have been online during the coronavirus pandemic. There also are a number of homeless tents lining the sidewalks in the area, including the sidewalk in the tunnel.

KUSI reported the incident happened in the 1400 block of B Street in downtown San Diego’s East Village.

More than 60 first responders were initially assigned to the scene, according to NBC7.

Lisa Brotzman said she was peering out of a window in her tent just as the car swerved to the right shoulder, “spun out of control” and jumped onto the sidewalk in the tunnel where people were waiting out the rain.

“Someone was screaming, ‘Ahhh! Ahhhh!’” Brotzman told The San Diego Union-Tribune. “Two or three people were yelling and screaming. It was scary.”

The driver got out of his car and tried to help people before identifying himself to police, Nisleit said.

“He was cooperative (and) did not try to run away,” the chief said, correcting earlier reports from police that he had tried to flee.

The Associated Press contributed to this report.