CHEHALIS — A woman was shot in the head late Tuesday night after exchanging gunfire with a Washington state trooper along Interstate 5 near Chehalis.

KOMO-TV reports the trooper stopped at milepost 70 near Napavine to help a woman, who pulled out a gun. The trooper and the woman exchanged gunfire.

The woman was shot in the head and airlifted to Harborview Medical Center in Seattle. The trooper was not hit.

Several lanes of I-5 were closed Tuesday night while authorities investigated the shooting.