IDAHO SPRINGS, Colo. -- Four people packed inside a van carrying suspected illegal immigrants died Tuesday when their van crashed on Interstate 70 around 2 p.m., just outside of Idaho Springs.

The driver of the 1998 Dodge minivan apparently lost control on the icy, slick roads and failed to negotiate a turn while going downhill on the eastbound lanes. The van ran off the road, slammed into several trees and then rolled, the Colorado State Patrol said.

Four people were ejected from the passenger side door and died at the scene. Police said three men and one woman were killed.

At least 10 others were injured and transported to St. Anthony's Central Hospital, 7NEWS reported, including one minor. The hospital said nine of the patients are men and one is a woman.

"It was pretty much a mess," said Sgt. Jack Vogt. "Some were kind of walking around. Some were lying around. At least 15 people were in the van that we know of."

The injuries of those taken to St. Anthony's range from minor to potentially serious, though a St. Anthony's spokeswoman said none of their injuries appeared to be life-threatening.

The driver of the van fled the area and reverse-911 calls were used to alert residents within a 2-mile radius of the accident scene. Police tracked the driver for four miles in the heavy snow conditions until they were able to catch him and arrest him four hours later.

Master Trooper Ron Watkins said federal immigration agents would take the unidentified man into custody.

The Jefferson County Sheriff's Office sent K-9 teams to sniff the driver out. It was not likely that the driver, whom victims said was paid to drive them through Colorado, can hide outside for very long.

"They have admitted they were here illegally," said Vogt. "They paid the driver to bring them here. He is apparently the only one who is a legal person here. He's the only one who took off on foot as far as we know. We imagine he is probably injured."

The driver was arrested and treated for hypothermia, police said. He faces numerous charges in connection to the incident.

The Immigrations and Customs Enforcement agency were on the way to the scene and to the hospital to question those involved.

"It's a pretty substantial search that we're setting up right now," said Vogt.

Eastbound I-70 at mile marker 241 was closed until the investigation completed. It was closed for several hours. Traffic was routed through Idaho Springs. The Colorado Department of Transportation said major delays could be expected on I-70 and alternate routes were strongly advised.

Weather conditions in the high country are deteriorating quickly, and there are several accidents within several miles of this one, according to the CDOT.

CDOT said conditions in the mountain areas along I-70 from the Mount Vernon area to the Vail area are worsening. Officials called it "snow squall-like conditions," where one minute it can be nice and the next minute it can be like being in a blizzard.

There are chain requirements for much of the area.