CONCORD (CBS) — A 32-year-old man is in critical condition after being pulled from Walden Pond in Concord on Saturday.

First responders were called to the pond around 7 p.m., according to the Middlesex District Attorney’s Office.

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First responders at Walden Pond in Concord on Saturday. (WBZ-TV)

First responders at Walden Pond in Concord on Saturday. (WBZ-TV)

Lifeguards are typically on duty until 6 p.m., but were not on scene when the man went under around 6:10 p.m.

Walden Pond in Concord. (WBZ-TV)

Walden Pond in Concord. (WBZ-TV)

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A Good Samaritan put on his snorkel gear, dove into the water, found the man and pulled him out.

Concord Fire Captain Bill Noke told WBZ-TV he had three divers enter the water and they helped the Good Samaritan bring the victim out. The victim had been under the water for about 15 minutes, he added.

The man was rushed to Emerson Hospital in Concord where he remains.

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No additional information was readily available.