Somerville Firefighter Michael Marino was on his way to report for overtime detail during a heavy storm on Saturday afternoon, when he approached a scene that just didn't look right.
"I noticed that there was an immense amount of water on the street," he said. "More than what we normally see in storms."
According to Marino, there was close to eight inches of water on McGrath highway as he approached a fork in the road leading up to the Assembly Square Underpass. There he saw an officer stopping traffic from entering the tunnel.
He stopped his car and asked the officer what happened and he told him there were people trapped in their vehicles. He had his gear in car and quickly slipped on his bunker pants and entered the tunnel.
More than 15 feet of water flooded the underpass, stranding four drivers in the rising waters.
He said there was no way for the drivers to know how high the water was because it was very difficult to judge.
"Everyone was driving through puddles that day."
Three of the drivers were able to swim ashore, but the driver of the furthest car out -- Christine Broderick -- was unable to swim and hung on to the roof rack of her Hyundai Santa Fe.
Marino took off his bunker pants and in a pair of workout shorts and a T-shirt entered the water.
"I knew it was a dire situation," he said. "I didn't have time to wait for a marine unit or a boat."
After reaching the 45-year-old woman, he talked to her and tried to explain the situation.
"I just tried to calm her down to make sure we both weren't in trouble if she panicked," he said. "It was pretty scary because you didn't know how high the water was going to rise."
Soon, Engine 1 arrived and had a life ring attached to a rope, but the crew was too far away. Marino swam over and they threw him the ring when he was about 10 feet out and he swam back and placed her on it.
"They were pulling the rope while I was swimming with her," he said. "The guys were out there forming a human chain" while they pulled us in.
Both Marino and Broderick were soon on land as the crew helped them out.
During his service in the Navy between 2002 and 2007, he spent time as a search and rescue swimmer, and said that experience, along with his department's swift water training, prepared him for his first water rescue.
"You train for it, but I had never been in this type of situation," he said. "We really worked well together. It was a well-oiled machine."