BANGOR, Maine — Arica Gagnon almost never takes Route 2 to get to Bangor from her home in West Enfield. But she did on Sunday, and it might be part of the reason University of Maine professor Nathan Godfried is alive today.

Gagnon, 32, a 12-year nurse who works at Health Access Network in Lincoln, was taking her three children, ages 5, 10 and 11, and two of their friends to Beth Pancoe Municipal Aquatic Center in Bangor that day for an afternoon swim, she said in a phone interview Tuesday. She had to drop something off in Passadumkeag on the way, so decided to take the less convenient Route 2, rather than Interstate 95.

While passing through Passadumkeag, she saw Godfried riding his bike along the opposite side of the road, heading north. She saw Godfried’s son riding on a bike just ahead of his father. Then Gagnon saw a truck carrying a trailer loaded with a tractor and rear-mounted mower heading north. The mower’s 8-foot metal blade was hanging well over the side of the trailer.

Gagnon realized what was happening and that Godfried had no idea what was coming up behind him. She slowed down and, through her rear-view mirror, watched in “what seemed like slow motion” as the lawnmower blade struck Godfried, sending him to the pavement.

Gagnon turned around, parking her vehicle about 200 feet behind the spot where Godfried went down. She hopped out of the car and rushed over to see what she could do to help.

“When I was approaching him, he was trying to get up,” Gagnon said. She urged him to stay down, concerned that though he was wearing a helmet he might have suffered a head or neck injury.

Then she saw his leg, which was “almost completely severed” about 2 inches below the knee, she said.

“I’d never seen anything quite as significant as that injury,” she said.

While a man in a nearby driveway called 911, Gagnon rushed to find something to use as a tourniquet. None of the bystanders was wearing a belt, so Gagnon grabbed her son’s new beach towel and used it to stem the flow of blood until paramedics arrived. She talked to Godfried and his son, who remained nearby. She checked Godfried’s pulse several times, which was “weak and thready.”

“He was alert, he was talking,” Gagnon said. “He was confused and was clearly in shock, but at least he was alert.”

Another woman who happened by the accident scene went to Gagnon’s vehicle to watch the five children and keep them busy and calm.

“It seemed like an eternity,” Gagnon said. “My main focus was just keeping this guy with us.”

When asked what her children thought of Sunday’s events, Gagnon said, “They think Mommy’s a superhero.” The children also have been asking about Godfried and how he’s doing.

Police say the “freak accident” occurred when the 8-foot blade on a John Deere mower being towed on a trailer by a truck came loose — falling from an upright to a lowered position — without the driver’s knowledge.

The sheriff’s deputy who went to the accident scene said the injuries could have been more severe if the driver hadn’t moved over in his lane to give the bicyclist more space, causing the blade to hit his leg and nothing else. Police believe that the mechanism that holds the mower blade up failed at some point during the truck’s trip.

Godfried, 62, was still listed in fair condition at Eastern Maine Medical Center in Bangor on Tuesday, according to a hospital spokesman. His left leg was fully amputated by surgeons, according to the head of the history department at UMaine, where Godfried is a professor. Attempts to contact Godfried’s family have been unsuccessful.

Gagnon said she sent a message to Godfried through the hospital, but has yet to hear back.

“I don’t expect to, necessarily,” she said. “But I just want to wish him and his family well.”

Gagnon said she’s glad she didn’t take her normal route to Bangor on Sunday.

“I just feel like there’s a reason that I was there,” she said.