Police said the accidents happened early Tuesday in Windsor on the northbound side. The interstate has been closed for several hours between exits 8 and 9.
Police said the first driver lost control of his vehicle and struck a guardrail. The second driver spun out and struck a guardrail while approaching the scene. A tractor trailer lost control and struck the second vehicle, which was pushed into a fire department truck. A firefighter was injured while escaping from the crash.
A fourth vehicle was passing by when it was struck from behind by a fifth vehicle.
Two of the drivers were suffering minor injuries and were taken to a hospital.