WESTBROOK — Mark Smith clung with two fingers to a small branch, struggling to keep from being swept down the raging Presumpscot River at dusk.

Then the 12-year-old boy, submerged to his neck, started losing the feeling in his hands. When three men scrambled down a steep embankment to help, Mark had been in the water for about 10 minutes and his face and hands were blue.

The next day, Mark said he owed his life to three heroes who rushed to the river and plucked him from the freezing water — Hugh Butler, Stephen Caron and Thomas Hanscome.

Mark, a seventh-grader, said he was “wicked” grateful and had one simple message for the men he didn’t know until Monday: “Just thanks for helping. I probably wouldn’t be here today if they didn’t.”

Mark said he was showing off his knowledge of the narrow, rocky path hugging the river’s canal near Bridge Street to two friends when he slipped on an icy rock and fell about 5:15 p.m. He slid several feet on his stomach into the water and was carried about 10 feet downstream.

Mark said he managed to grab the branch with his right hand, but couldn’t pull himself out of the water because of the strong current. He was just 30 feet upstream from rapids and a stretch of open water with strong undertows and submerged rocks and trees.

His friends screamed for help, alerting Cynthia Murphy as she was walking across a nearby bridge. Murphy dashed into a nearby restaurant, enlisting Caron, Butler and Hanscome to Mark’s aid.

The boy was taken by ambulance to Maine Medical Center in Portland for treatment of hypothermia. Mark said he was covered with blankets in a hospital room for about four hours before his mother was allowed to take him home.