Police have identified a woman was swept away in a swollen river while trying to save her dog.
Search and rescue teams were stood down late Monday night
Police said they "strongly believed" the 40-year-old woman who jumped into the River Stour at Blandford, Dorset, was Caroline Peck, from Salisbury.
Her next of kin has been informed. Two passers-by tried to save her including a 59-year-old man who had to be pulled to safety and airlifted to hospital.
The rescue began on Monday afternoon but was stood down when it got dark.
The operation involved Portland Coastguard's rescue helicopter, Poole Coastguard Rescue Team, Dorset Fire and Rescue's swift water rescue team and Dorset Police marine section officers.
The woman was reported missing at 1530 GMT.
Police officers and the marine boat resumed searching at first light in the hope she may have climbed to safety.
Speaking on Monday evening, Ros Evans, Portland Coastguard watch manager said: "Sadly we have not been able to find any sign of her yet.
"She was seen being swept down river after attempting to rescue her dog.
"We would like to take this opportunity to remind members of the public about the dangers of rivers whilst swollen."
The woman's dog escaped unharmed.