The collision occurred in New Haven County at a railroad crossing on Sackett Point Road in North Haven at 5:50 a.m. on Friday, Aug. 9.
North Haven Police said an investigation is underway, and commuters are asked to avoid the area and expect delays.
Only minor injuries were reported, North Haven Police said. A train engineer was hospitalized.
North Haven Fire Department officials said the train was able to stop approximately a quarter-mile from the crossing. The train was carrying approximately 107 passengers, none of whom reported any injuries.
Passengers were being transferred to another train.
Police are reporting extensive damage to the tractor-trailer and nearby utilities, which will cause a lengthy delay for drivers on Sackett Point Road.
This is a developing story. Check back to Daily Voice for updates.
Click here to follow Daily Voice Darien and receive free news updates.