EAST MILLINOCKET, Maine — The family of an elderly patient injured when the town ambulance she was in slid off Interstate 95 in Edinburg on Monday questioned whether the ambulance’s driver was mindful enough of icy conditions.

Barbara Carter, 72, of East Millinocket suffered a knee injury and heavy bruising from the right side of the top of her head to the left side of her lower lip when the gurney she was strapped to broke free as the East Millinocket-Lincoln ambulance rolled over once and came to rest on its wheels on the southbound side of I-95 on Monday, she said.

Carter was going from Millinocket Regional Hospital to Eastern Maine Medical Center in Bangor for heart surgery. She said she was dozing but also in conversation with East Millinocket paramedic Harvey Frederick when the accident occurred.

“I kind of knew something was rolling. I was watching the windows go around,” Carter said Tuesday by phone from EMMC. “I don’t really remember everything, but they said that it let loose, the thing I was on. I believe it unhooked or something. I heard them say that, that it unhooked.”

Carter’s husband and son questioned whether ambulance driver Louis Perreault was driving too fast for conditions. Both wearing seat belts or safety harnesses, Perreault and Frederick were treated and released from EMMC after the accident.

“This is the kind of stuff that happens in movies. I had never heard of this. I was just stunned and concerned,” said her son, Harold L. Carter III, of Saco, a Portland parking control officer. “I’m a little bit angry and upset at this. Quite honestly she looks like she had been through a boxing match — and lost.”

“If somebody is at fault for this, I think that person should be disciplined,” Carter added. “If it turns out that they weren’t going too fast and it was just an accident, I am OK with that too.”

East Millinocket Fire Chief Les Brown is on vacation and unavailable, firefighters said. Fire Capt. Peter Larlee, who is filling in for Brown, said he was told to refer comment on the matter to town Administrative Assistant Shirley Tapley.

Tapley said she didn’t know what action town leaders would take, if any, in response to the incident.

“I will have to wait for the police report,” Tapley said before terminating the interview.

State police Trooper Trevor Snow is investigating the incident. Snow said Monday that he did not expect to press charges in connection with the accident, which seemed, he said, to be caused by icy conditions.

Having determined that the accident wasn’t caused by negligence, Snow said Tuesday that he won’t be seeking to learn how fast the ambulance was going when it went off the road.

Several minor accidents were reported on I-95 on Monday morning and more than 50 accidents, mostly vehicles sliding off the road, were reported on the highway and on state roads on Sunday night.

Conditions were so slippery that a large-wheeled pickup truck towing a horse trailer and horse slid off the road into a guardrail near Lincoln about 15 minutes before the ambulance rolled over.

Carter’s husband, Harold L. Carter Jr., said he had driven the highway from East Millinocket to EMMC before the accident occurred. He was amazed at how fast some vehicles were traveling in the obviously unsafe conditions. Several others had slowed considerably, he said.

Ambulance rollovers are rare, but Snow said they can occur because the multi-ton vehicles are top-heavy and likelier to tip over in adverse conditions than most other transports.

Ambulance services share with the sending medical facility responsibility for the health of patients being transferred, but decisions regarding whether to transfer patients in bad weather are usually made by the ambulance service in consultation with doctors, said Chuck McMahan, a paramedic and chief operating officer of Meridian Mobile Health, which does business as Capital Ambulance.

Eastern Maine Healthcare System policy requires that its ambulance services obtain current weather and road conditions from the National Weather Service, Maine Department of Transportation and Maine State Police, McMahan said.

Services are advised to delay transfers until the weather improves if conditions make travel inadvisable and patients do not require immediate care. If the weather remains bad and the patient’s care is critical, EMHS members work with patient physicians and the service staff to determine whether “the transport can be accomplished safely, and [if] the benefit of transfer outweighs the risk to the patient and crew,” McMahan said.

Capital, Sebasticook Valley Hospital, Crown Ambulance Service of Presque Isle, C.A. Dean Memorial Hospital of Greenville and LifeFlight have transport services and belong to EMHS, McMahan said.

Capital Ambulance, which handles about 12,000 ambulance runs annually, operated ambulances on Monday, but temporarily suspended a patient transfer to Boston on Sunday night prior to I-95’s shutdown, McMahan said.

“There was no immediate need for the patient to go,” he said.

Carter said her heart surgery, to insert two stents into her arteries, will be postponed until she heals from her accident injuries. Two stents were inserted a week ago, Carter said.