The New Hampshire State Police are investigating the death of a Concord, NH woman who died in the Merrimack River on Sunday.

CONCORD, NH. (WCAX) - New Hampshire State Police is investigating the death of a woman in the Merrimack River. Police say it happened just before noon Sunday when 67-year-old Claire Knowles was swimming after her tube in a mild current in the river, and as she returned to shore, she suffered a medical event.

Claire Knowles, 67, of Concord, was swimming after an inflatable tube in mild current Sunday morning when she suffered a medical emergency returning to shore, New Hampshire State Police said.