SAN DIEGO >> The pickup involved in the crash that killed three people during a rainy pursuit by U.S. Border Patrol agents had just driven across the international border in a human-smuggling attempt, the federal agency said today.

Eleven people were in the Chevrolet Silverado pickup — nine of them in the bed, which had no camper shell — when it crashed along westbound Interstate 8 near Crestwood Road on Thursday afternoon.

Everyone but the driver was thrown from the truck.

The driver of the pickup was identified today as Luis Alberto Virgen, 21, a U.S. citizen who has been living in Tijuana, California Highway Patrol officer Travis Garrow said. The passengers are not believed to be U.S. citizens, he said.

Virgen was arrested on suspicion of three counts of gross vehicular manslaughter and is expected to be arraigned next week. He remained jailed today in lieu of $50,000 bail, according to online jail records.

The Border Patrol today said that at about 4:10 p.m. Thursday, its agents spotted tire tracks from multiple vehicles near the U.S.-Mexico border. The tracks crossed into the United States and headed north.

That, the agency said, is indicative of what its calls “a drive-through smuggling event” — smugglers driving people across the border.

Along with the tracks, agents found a piece of a vehicle. Officials did not specify what type of car part it may have been.

Ten minutes later, agents spotted the Silverado — and it was missing the same part that had been found near the suspicious tire tracks.

Agents gave chase, lights and sirens on, the Border Patrol said.

The fleeing truck raced off and jumped on to Interstate 8 at Buckman Springs Road, and headed east roughly 15 miles before getting off at Ribbonwood Road. But it got right back on the freeway — this time heading west.

According to a CHP incident log, witnesses reported the pickup was weaving in and out of traffic and passing other motorists using the center median and right shoulder at speeds of more than 100 mph.

The Border Patrol said its agents rolled a spike strip out across the freeway east of Crestwood Road, which is near the Golden Acorn Casino.

The speeding truck ran over the strip, and about a minute later, the vehicle headed up a dirt and rock embankment along the freeway and rolled.

It was raining at the time of the crash.

Ten of the 11 people in the truck were thrown. Three of them — two men and the sole woman in the truck — died. Eight others sustained injuries ranging from moderate to major.

The woman who was killed had been in the cab of the truck. The remaining passengers were in the bed.

No further information about the people in the truck was available, including their names, ages or country of citizenship. Garrow said the passengers have not yet been identified.

“We are still working on that,” he said.

When it comes to chases, the policy of the Border Patrol states that agents may engage in pursuits only when the benefit outweighs any immediate danger created by speeding or other emergency driving techniques.