PORTLAND – The search for a missing South Berwick woman may have saved the life of another woman who was trying to kill herself.

Portland police and the Coast Guard were searching for Amy St. Laurent on Wednesday when they spotted a woman who was trying to drown herself in Casco Bay.

St. Laurent, 25, was last seen in Portland on Oct. 21.

Portland police Detective Richard Swift and Coast Guard Petty Officers John Stevens and James Wojtkowski were in a Coast Guard boat, scanning the shores from the Fore River to Back Cove for signs of St. Laurent. They saw a person swimming away from shore about 100 yards from the city’s sewage treatment plant.

The men were instantly concerned because the water temperature was 48 degrees, according to Police Chief Michael Chitwood.

When the boat approached, the swimmer changed direction and headed back to shore.

The rubber boat could not get close to the woman because of rocks in the water.

The men called the police department and the Coast Guard base in South Portland, and officers were waiting for the woman when she reached the shore.

Chitwood said the woman told the officers she was trying to kill herself.

She was taken to Maine Medical Center and was involuntarily committed for a check on her mental stability.

“They’re out looking for a young girl who is missing and their actions saved a young lady’s life,” Chitwood said.