OLD FORGE, N.Y. — In a remarkable showing of vigilance and courage, a school bus driver helped save the life of a woman trapped in her car in a frigid pond.

Shawn Marie Chesebro, a driver for the Town of Webb Union Free School District, was returning from a morning run on Jan. 3 when she noticed skid marks and tracks leading off the icy road. Because of her high vantage point, Chesebro was able to see over a snowbank and spot the protruding wheels of an overturned vehicle in a pond.

Chesebro attempted to call for help first on the radio and then on her cell phone, but neither was getting reception in the area. She knocked on the door of a nearby house, but there was no answer.

Chesebro could tell that no one had exited the overturned car, so she jumped into the pond, with the icy water reaching up to her waist. She saw someone in the car, but the doors were locked. Using large chunks of frozen pond, Chesebro attempted to break a window.

After she had been in the water about five minutes, she was able to wave over a passing motorist, who has not been identified. The man brought Chesebro a tire iron, which she used to break a window, and helped her pull out the woman.

Someone in the nearby house had called 911, and emergency responders arrived at the scene. The driver, Michal Pederson, 60, was taken to a hospital, where she was treated for mild hypothermia and released.

It was estimated that Pederson was in the water nearly 20 minutes. She later said that, though she was able to capture breaths by bobbing to the surface, she had just run out of energy, said her goodbyes and was ready to die when Chesebro arrived.

Chesebro, who is in her fifth year of driving for the Webb district, said there was no time to hesitate or think about the frigid water she was getting into. “I just realized that there was no other option. I knew that I had to get in there and get the person out,” she said.

Chesebro and Pederson have since kept in touch, chatting every few days. About a week after the rescue, state police came to the Webb transportation department and gave Chesebro a certificate of appreciation for her heroism.

Herb Schmid, supervisor of the district’s 15-bus operation, said that he and the rest of the department are proud of Chesebro’s brave actions. “It was quite a feat,” he said. “The police said there was no doubt that [Pederson] would have drowned if it hadn’t been for Shawn. Emergency response to that area is 10 to 15 minutes.”

The district encompasses 566 square miles in and around the Adirondacks.