SANTA CRUZ — One man is dead and another in critical condition after a white Cadillac plunged off the Santa Cruz Municipal Wharf about 8:20 p.m. Saturday.

Santa Cruz Fire Department Rescue Divers freed one man from the submerged vehicle at 8:55 p.m. and swam him to Cowell Beach on a paddle board. CPR was administered for roughly 20 minutes before he was transported to Dominican Hospital.

Wharf Maintenance Divers pulled the second man from the vehicle at 8:59 p.m. Rescuers swam him out to a Coast Guard boat, which rushed him to the Santa Cruz Small Craft Harbor where a waiting ambulance transported him to Dominican Hospital.

Although Santa Cruz fire Battalion Chief Mike Ditano said it was not clear what caused the driver to drive off the wharf, eyewitnesses Tyler Groch, 29, and Brittney Groch, 25, both of Newark, said the Cadillac swerved to avoid a Dodge Dakota leaving the wharf.

“The Dakota was blasting loud music as it passed us,” Tyler Groch said. “We heard it slam on its brakes and this screeching. When we turned, we saw the white sedan swerve off the wharf, away from the Dakota, toward the railing,”

“At first we thought it was just going to park, but it kept going,” Brittney Groch said.

“It barely missed a family of four or five before hitting the rail,” Tyler Groch said.

The Cadillac bounced over an 8-inch parking block and tore through a section of 4-foot guard rail located between the Santa Cruz Lifeguard Headquarters and the first business on the west side of the wharf, which sells shaved ice.

“It didn’t go right in. It teetered for a few seconds on the edge of the wharf before finally tipping over and falling into the water,” Tyler Groch said.

The Cadillac plunged roughly 20 feet from the wharf and quickly sank from sight into dark, 61-degree water. According to witnesses, the driver-side passenger window of the vehicle was open at the time of the crash.

“People on the wharf were shining lights into the water, and they said it was a car, and I said, ‘Oh my God,’ ” said Mara Torres, of Felton.

Torres’ blue Toyota was parked next to the crash site.

Immediately after the crash, a woman identified herself as a lifeguard and ordered the growing crowd of bystanders to stay back from the edge and remain on the wharf. She jumped from the wharf into the water and made an unsuccessful effort to locate the vehicle, which had sunk into 25 feet of water with both occupants still inside. She refused to give her name.

Santa Cruz Fire Department Rescue Divers and Wharf Maintenance Divers in swim fins and wet suits responded to the scene within 10 minutes of the first responder call. A crowd of at least 70 bystanders watched the drama unfold from above, many of them shooting video or taking photos with their cellphones.

Two hours after the crash, three scuba divers entered the water and attached straps to hoist the Cadillac from the water with a crane. At 11:15 p.m. firefighters lifted the vehicle from the water. Its roof was caved in and its windshield smashed.

Santa Cruz Police are asking anyone who may have information about the incident, or may have witnessed the incident, to contact Detective Bruce Cline #189 at the Santa Cruz Police Department Investigations Section at (831) 420-5820.