A vehicle flew off a Colorado highway overpass Thursday, smashed into a concrete barrier and burst into flames, killing all seven people inside, police said.

The Colorado State Police said in a news release that the victims, whose names weren't released, included an infant and a toddler. They were pronounced dead at the scene by the Larimer County coroner after police arrived at 4:38 a.m.

Troopers said the 1992 Chevy Suburban ran off the left side of northbound Colorado 25 at marker 253 in Larimer County and continued northward until the center median ended, sending the sports utility vehicle falling from an overpass to Colorado 60.

Police said the vehicle collided with a concrete barrier and rolled until it came to rest on its wheels and was engulfed in flames.

Investigators said it was not yet known whether alcohol, drugs or speed were factors in the crash. They said they were working to identify the victims.