LANCASTER, N.Y. (WIVB) — A man is dead following a Monday crash in Lancaster between a van and tractor trailer.

Police in Lancaster responded to the scene of a crash on Genesee Street near Harris Hill Road just before 12 p.m. Officers say they believe the man driving the van crossed the center of the road, striking the tractor trailer.

The crash killed the 42-year-old driver of the van, with first responders on the scene pronouncing him as dead. Officers have yet to release the man’s identity.

A full investigation is underway, as police say they’re not yet sure what led the man to shift lanes into the semi’s path.