BOSTON (CBS) – Massachusetts State Police are investigating why a woman got out of a car in the middle of the O’Neill Tunnel during rush hour. She was hit by another car and suffered life-threatening injuries.

It happened just after 7:30 a.m. near Exit 23.

State Police said the 29-year-old Mattapan woman was found injured in the middle of the road.

It is not yet known why the woman, who was a passenger in the 2012 Mazda CX9, got out of the car on Interstate 93 south. She was hit by a 2015 Jeep Cherokee being driven by a 31-year-old Charlestown man.

The woman was rushed to Tufts Medical Center and remains in critical condition.

The driver of the car that hit the woman and the woman’s hired driver both remained on scene.

State Police said the Mattapan woman was picked up at Logan Airport Terminal C by a 27-year-old woman who was driving the Mazda for Uber. The driver agreed to bring the passenger to the agreed-upon location in Mattapan.

According to Uber, there is no log of the ride and they believe the driver could have been soliciting rides or driving on her own.

Police are still investigating the incident.

Several lanes were closed in the aftermath of the incident but have since reopened. Significant traffic delays resulted.