California crash kills at least 13 people: What we know about the SUV-semitruck collision near US-Mexico border

Authorities were still searching for answers Wednesday after at least 13 people in a packed SUV were killed as the vehicle collided with a semitruck near the U.S.-Mexico border Tuesday.

A 1997 Ford Expedition, with seats removed, had 25 people inside when the big rig slammed into the side of it at the intersection of State Route 115 and Norrish Road near Holtville, California, said Omar Watson, Highway Patrol Division chief.

Federal authorities also said late Tuesday they were investigating any possible links to human smuggling. The crash occurred about 10 miles north of the border, and a Mexican government official said at least 10 of the victims were Mexican nationals.

"It would be premature for me to speculate or discuss what caused this collision. What we have to keep in mind is that 13 people died in this crash," Watson said. "It’s a very sad situation."

Breaking news:At least 13 dead after truck slams into SUV carrying 25 near US-Mexico border

Here's what we know now:

What happened in the crash?

A preliminary report released Tuesday by the highway patrol said the SUV, driven by a 28-year-old resident of Mexico, "entered the intersection directly in front" of a Peterbilt truck. Police said it wasn't clear why the SUV entered the intersection, but the truck struck its left side, immediately killing its driver.

Watson said 12 people were killed at the scene and a 13th person later died in the hospital.

Several people inside the SUV were flung from the vehicle while others managed to get out by the time police responded, Watson said. A few others had to be freed from the SUV.

Who was killed and injured in the crash?

Police have not released the names of the victims of the crash. The ages of those in the SUV range from 15 to 53. No children were killed in the crash, police said.

The SUV's driver was from Mexicali, Mexico. Roberto Velasco, director of North American affairs for Mexico’s Foreign Relations Department, confirmed that 10 of the people killed were Mexican.

Watson said the California Highway Patrol was working with the Mexican consulate to "determine who exactly was in the vehicle." What's "important to me is to make sure the families are notified and that we do a thorough investigation so that we know what the cause of the collision was," he added.

Passengers' who survived had injuries ranging from minor to severe, officials said. At least one person was already released from an area hospital, Watson said.

The truck driver, Joe Beltran, 68, of El Centro, California, was also taken to the hospital with "major injuries," the preliminary crash report said.

Why were so many people in the SUV?

Watson said investigators were still searching for answers as to why more than two dozen people were in the SUV.

Police did not immediately know where the Ford Expedition was coming from or where it was going, he said.

Only the driver and front passenger seats were in the vehicle at the time of the crash, Watson said.

"I don’t know if they were cut out or removed, but they were not in the vehicle,” Watson said of rear seats in the SUV.

In a statement, U.S. Immigration and Customs Enforcement said special agents from its Homeland Security Investigations unit in San Diego "have initiated a human smuggling investigation," but offered no further details.

Macario Mora, a spokesman for Customs and Border Protection in Yuma and El Centro, said Border Patrol was not pursuing the vehicle at the time of the crash.

“It was an unusual number of people in an SUV, but we don’t know who they were,” Mora said, adding that they could have been farmworkers. A harvest is underway in the region, where farmworkers will collect most of the winter lettuce and other leafy greens eaten in the United States.

Contributing: Grace Hauck, Colin Atagi, Christal Hayes, Emily LeCoz and Janet Loehrke; The Associated Press