KEENE, N.H. (MyKeeneNow) A head-on collision involving three vehicles, including a motorcycle, shut down a stretch of Route 9 West Sunday morning and left seven people hospitalized.

The Keene Fire Department said the crash happened around 10:30 a.m. near the Westmoreland town line. Responding crews arrived within minutes and found two heavily damaged passenger vehicles and a motorcycle. One person was trapped inside a car and had to be freed using specialized rescue equipment.

Because of the number of injured people, officials declared a Level 1 mass casualty incident, prompting additional ambulances and rescue units from Spofford, Cheshire County, and Rescue Inc. to assist. A DHART medical helicopter was also called in to fly one seriously injured patient to Dartmouth Hitchcock Medical Center in Lebanon.

In total, four patients were taken to Cheshire Medical Center in Keene, two to Brattleboro Memorial Hospital in Vermont, and one by helicopter to Dartmouth Hitchcock. Authorities said all the victims were conscious and breathing at the scene.

Fire officials credited mutual aid partners, Keene police, state police, dispatchers, and hospital staff for their cooperation in handling what they described as a “complex incident.”

Both cars involved in the collision were considered totaled. The motorcycle’s condition was not immediately known.

The cause of the crash remains under investigation by the Keene Police Department, which is handling questions related to responsibility or the identities of those involved.