Three people were killed Wednesday morning when a livery vehicle crossed an Interstate 195 median in Westport and struck a car in a head-on collision, causing a chain reaction of three other crashes, State Police said.

Two people in the livery vehicle, a 2005 Dodge Caravan, were killed in the collision, State Police said in a statement. The agency did not release the names of the victims or the livery service because officials are still working to notify their families.

One person in that car survived the crash and was taken to Rhode Island Hospital.

A 23-year-old New Bedford woman was killed in the BMW that was struck by the livery car, State Police said. A 25-year-old Fall River man, also in the BMW, was taken to Rhode Island Hospital, and a toddler was taken to Hasbro Children’s Hospital.

State Police said the Dodge Caravan was going west between exits 10 and 11 when it crossed the median around 8:12 a.m. and struck the BMW, which was in the leftmost eastbound lane.

The crash is under investigation. State Police said they haven’t determined why the car crossed the median.

After the initial collision, the Caravan rolled over on the highway and struck an Audi A4, State Police said. The Audi driver suffered minor injuries and was taken to Charlton Hospital.

Meanwhile, a Subaru rammed into the BMW and then caught fire. The 27-year-old Vermont man driving the Subaru was taken to Rhode Island Hospital with minor injuries.

A Chevrolet Suburban was also involved in the crash, but State Police didn’t mention any injuries to that driver.

The entire eastbound side of Interstate 195 and the left lane of the westbound side were closed as police investigated the accident.

Dylan McGuinness can be reached at dylan.mcguinness @globe.com. Follow him on Twitter at @DylMcGuinness.