The crash occurred at about 5:40 p.m. on I-95 southbound between Exits 17 and 16, Assistant Fire Chief Jeff Gootman said.
Westport Engines 4 & 2, Car 3 and Rescue 3 responded to the call along with units from the Norwalk Fire Department.
A car was on fire in the left lane when firefighters arrived, with two additional vehicles from the accident in the right lane, Gootman said.
Westport Engine 4 stretched a single hand line and extinguished the fire quickly with backup from Engine 2. Rescue 3, Westport EMS and Norwalk EMS treated and transported four people from the cars in the right lane, he said.
There were no injuries in the vehicle that was on fire.
According to State Police, southbound I-95 traffic was backed up for an extended period due to the fire.
The last Westport Fire Department unit cleared the scene at 6:54 p.m.
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