Four people were sent to the hospital after a four-vehicle crash in North Haven, close to the Hamden line, Friday morning.
Firefighters from North Haven said they responded to the crash on Dixwell Avenue just before 6 a.m.
It happened at the intersection with Hartford Turnpike.
The road in the area was closed.
"This was a very serious crash involving multiple vehicles and multiple patients," said Chief Paul Januszewski, North Haven Fire Department. "I want to commend our firefighters for their diligent work in assessing the patients and rescuing multiple trapped occupants."
Investigators initially found that a 2013 Hyundai Santa Fe was driving westbound when the driver crashed into a 2005 Toyota Rav 4.
The force of the impact sent the vehicles into two others that had been stopped at the intersection.
Five people were involved in the crash, but four required transportation to Yale-New Haven Hospital, according to firefighters.
They said a 43-year-old man and a 38-year-old woman in the Hyundai suffered serious injuries. They had been thrown from their seats and had to be extricated.
A 30-year-old man and a 40-year-old woman who were in the vehicles that were hit were also transported, though their injuries didn't appear to be serious.
Conditions were dark at the time of the crash.
The cause remains under investigation.
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