Dennis Fire and Rescue crews responded to the area of 312 Setucket Road between Old Bass River Road and Route 134 at 9:52 a.m.
According to Captain Wayne Conlon of the Dennis Fire Department, there were four total passengers involved in the two-vehicle crash including two women and 2 young children.
Dennis crews transported Trude Maloney, 69, of Dennis, to Wixon Middle School for a medflight to Massachusetts General Hospital in Boston with life-threatening injuries.
Maloney was traveling west on Setucket Road when her Toyota Matrix crossed over the center lane into the eastbound lane colliding with a Ford Taurus wagon.
Rita Taylor, 83, also of Dennis, and two grandsons, 12 and 5 years of age, were transported to Cape Cod Hospital in Hyannis with non life-threatening injuries.
Taylor and her grandsons were traveling eastbound and pulled to the side of the road when the other vehicle crossed lanes and came to a stop before being struck.
Yarmouth Fire Department assisted with transporting two of the patients to CCH.
Dennis Police assisted on scene and are investigating the cause of Maloney traveling into the wrong lane.
Authorities closed the road for approximately 45 minutes to transport the victims and remove the vehicles.
Conlon said the Jaws of Life were used to free one of the passengers that was taken to CCH.