Five people have been released from the hospital, including three Greenwich firefighters, after a tractor-trailer crashed into a fire engine on the scene of an earlier accident on Interstate 95.

The two crashes shut down part of I-95 southbound for several hours into the Thursday morning commute, backing up traffic for miles.

Connecticut State Police said the first crash happened just after 11:30 p.m. Wednesday near Exit 4 in Greenwich when a tandem tractor-trailer in the center lane began to swerve right, hitting the right shoulder guardrail and light pole before rolling over. CSP, the Greenwich Fire Department and Greenwich EMS responded.

“They helped extricate a patient who was then transported to the hospital,” explained Assistant Fire Chief Charlie Lubowicki. “They also mitigated a diesel spill. Once they did that, they returned to their engine.”

The fire engine was set up on the right shoulder in a blocking position to protect the crews ahead, including several workers from Lone Star Repair Services in Stamford, who were on scene to tow the tandem tractor-trailer.

“We're working and next thing you know we hear tires screeching and a crashing like real loud booms and bangs, and we turned around to look behind us and you could see a tractor trailer going sideways,” recalled Fulvio Tamburro, owner of Lone Star. “We literally saw the truck coming towards the accident scene. We ran. We literally ran away from it. We didn't know what was going to happen. People scrambled all over.”

Tamburro said that when the smoke cleared, he and his employees saw the tractor-trailer had hit the fire engine. It happened just after 1 a.m. Thursday. Three firefighters were in the rig at the time. The driver had to be extricated, according to Lubowicki. “Engine One was moved over 100 feet from the impact, which obviously is a lot of force for a 40,000-pound truck to move that far,” Lubowicki told News 12. He said the three firefighters went to the hospital with “serious but non-life-threatening injuries.”

The driver of the tractor-trailer had to be extricated, as did the driver of an SUV that was also hit, with both also going to the hospital.

Lubowicki credited the cool-headed actions of the department, but also acknowledged it was a tough situation.

“This was a very traumatic thing,” Lubowicki said. “The crews on scene did a fantastic job under the stressful situation of assessing what happened and realizing what had to be done. They all came together to help rise to this occasion to make sure everything that had to be done was completed in the most effective way possible.” Tamburro, who’s been on the job for 34 years, said he’s unfortunately gotten used to cars flying by him way too closely, but this was his closest call. “It really hit home. It's going to take a few days to wear off. It was something I can't describe,” Tamburro told News 12. “My whole crew was devastated by it. We felt it the rest of the morning. Everybody was like looking over your shoulder every time you heard something out of the ordinary. People need to slow down and move over when there's any type of emergency vehicle on the side of the road--not just police, but state workers, tow trucks, ambulance, all of us. It's very important.”

Tamburro also thanked firefighters for always protecting him and his workers at any crash site.

“They're like our guardian angel if you will. I mean, look at today. They really protected that whole scene. It could've been so much worse had they not been there,” Tamburro said.

Lubowicki said the firefighters will off the job for some time as they recover physically and mentally. The department will also be doing peer support for all their members over the next several days.

“A lot of this can wear on you as a first responder,” he explained. “In the day to day, being a first responder is a dangerous thing, and you could run into dangerous situations, and that's just ramped up when you are on I-95.”

Lubowicki told News 12 that about 15 years ago, another fire engine was also hit while at a crash on I-95.

“The Greenwich Fire Department probably responds to, on average, at least one accident a day between I-95 and the Merritt Parkway, definitely increasing our odds of having members injured or apparatus hit in a collision like this,” Lubowicki stated, adding the damage to the fire engine is severe. He said it will be out of service for some time and could possibly be totaled.

CSP is investigating the crash. The agency said the tractor-trailer that slammed into the fire engine was unregistered and uninsured.