Three men were killed and a fourth was wounded in a drive-by shooting Thursday night in North Richmond, the deadliest single incident in the unincorporated community since the 1990s, authorities said Friday.

Lawrence Gadlin, 23, of Berkeley, Gerald Jackson Jr., 34, of Richmond and Tony Albert, 51, of North Richmond died after they were shot by at least two gunmen in a minivan on the 1700 block of Truman Street at about 9 p.m. Thursday, said Capt. Steve Warne of the Contra Costa County Sheriff's Office, which patrols North Richmond.

Gadlin and Albert were pronounced dead at the scene, and Jackson died at Doctors Medical Center in San Pablo.

The fourth victim, whose name was not released, was treated at John Muir Medical Center in Walnut Creek and released.

On Friday morning, a young man who several people on the block said was the surviving victim stood outside a house at the shooting scene talking with a half-dozen other men, but refused to comment. He had been shot in the left side, neighbors said.

The four shooting victims were working on a car when at least two people in a red minivan with tinted windows unleashed a fusillade at them, Warne said. He declined to discuss the type of guns used.

No arrests have been made, but authorities found what they believe was the shooters' minivan Friday morning in Richmond, Warne said.

The killings may have been gang-related, Warne said, although investigators do not know if the victims were associated with a gang or were simply targeted at random by gang members.

The shootings happened on a block of weather-beaten bungalows. On one side of the street, a green minivan had one passenger-side window and the back window shot out, and on the other was a beige house with four fresh bullet holes in the garage door.

Residents nervously peered through their windows as two groups of a half-dozen young men milled around near the garage and the shot-up van. When asked to comment, the men either asked for money or angrily rebuffed questions.

"We heard 10 shots, bam-bam-bam, and when I ran out I saw three people lying face down in the street," said Nancy Villanueva, 19, who lives near the scene. "About 20, 30 people were running away, and the fourth guy who was shot but wasn't dead was lying on his stomach looking like he was praying."

Asked if there were gangs on the street, Villanueva said, "I know they're in town, but sometimes it's better not to ask."

She said there had been two shootings in nearby blocks in the past three months, "but this street's not so bad."

A few houses away, three members of the Suns of Light Grand Masonic Lodge gazed at the bullet-riddled van and shook their heads. They were there refurbishing their lodge meeting house, with the hopes of launching after-school programs for youngsters in the area.

"What we need around here is more positive things for young people to do," said Cecil Booker, the lodge's grand junior warden. "You want a prime example of why, it's right there" - and he pointed at the van.

Warne said the shooting may have been in retaliation for an incident Thursday morning in North Richmond in which shots were fired but no one was hurt.

"The last time we had an event of this magnitude was in the late 1990s, when we investigated a quadruple homicide," Warne said. "Most recently, it seems like the violence had started to subside in the area. But yesterday's incident is an indication of, you know, possibly not, so we're concerned about that."