FAIRFIELD, Conn. (AP) Connecticut State Police are trying to determine why a 27-year-old woman was weaving in and out of traffic at high speeds on Interstate 95 in Fairfield before she crashed into a tractor-trailer and died in a fiery wreck.

Troopers say Yvonne Sokol was driving erratically Sunday morning when her car struck the truck and burst into flames in the northbound lanes near Exit 22. Authorities say Sokol was trapped in her mangled car under the truck and was pronounced dead at the scene.

No one else was in her car, and the truck driver wasn't hurt.

The accident caused major traffic backups on the highway for several hours.