CHICAGO (CBS) — Police are trying to figure out what led to a crash in Channahon yesterday afternoon that took a mother’s life and injured two girls.

46-year-old Carolyn Grey was killed when her SUV collided with a semi tractor at the intersection of Route 6 and Bell Road at 3:30 p.m. according to Police chief Joe Pena.

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He describes the scene as horrific. He said it took hours to extract Grey from the vehicle, which was wrapped around a light pole.

Pena says some people driving by helped get Grey’s roughly 8-month-old daughter out of the car before emergency personnel arrived.

It took the fire department about 45 minutes to remove Grey’s 4-year-old daughter, who was then taken to a Downers Grove hospital, he says.

The truck driver was not injured and has not been cited in the crash.

Investigators are working to reconstruct the accident.