State Police have released the identities of four people killed in a head-on crash Monday morning. A car and sedan collided while one vehicle was trying to pass a tractor trailer. One man was injured and is being treated for serious but non-life threatening injuries. Police say the driver of the car was pregnant.

Trooper Chuck Michaud said in a press release that a southbound SUV was attempting to overtake a tractor trailer on Route 161, north of Caribou, when it struck a northbound sedan head-on. The driver of the SUV, Kimberley Lausier, age 38 of Madawaska, was killed in the accident along with three occupants of the car. All four people were pronounced dead at the scene. Police confirmed on Tuesday that Lausier was pregnant.

A passenger in the SUV, Robert Lausier, age 53, survived the crash with serious injuries to his lower extremities that are not considered life threatening. Lausier was taken to Cary Medical Center in Caribou, and later transferred to EMMC in Bangor.

Killed in the sedan were: driver, Bobbi-Jo Johnston, age 33 from Fort Fairfield; her mother, Laurie Ann Johnston, age 52 from Carlingford, New Brunswick; and Alana Nelson, age 2, daughter of Bobbi-Jo Johnston.

Assisting in the rescue, reconstruction, and follow-up were North Lakes Fire Department personnel, Warden Alan Dudley, Trooper Marc Poulin, and the North Lakes Fire Department. Route 161 was closed for several hours during the investigation with traffic detoured onto the Cove Road.

State Police interviewed witnesses but haven't spoken with the operator of the tractor trailer, who police say may not have realized the crash occurred. State Police are asking if someone was operating a box-style trailer southbound on Route 161 near Rainbow Cove at the time of the crash, that they contact the State Police in Houlton at 532-5400.