A woman was killed when she was swept over Niagara Falls, according to news reports.

Witnesses said the woman appeared to be alive as she approached the brink of the Horseshoe Falls about 4:30 p.m. Tuesday, reported CNN affiliate WIVB-TV in Buffalo, New York.

The Maid of the Mist, the vessel that takes tourists to the foot of the falls in the Niagara River, dispatched a boat to help her, but she was dead when it reached her, according to the WIVB report.

The woman has not been identified, and her death is under investigation by the Niagara Parks police and Niagara Regional Police, according to a report in the Niagara Gazette. Foul play was not suspected, WIVB reported.

On Monday, two men in a small boat came within 700 feet of the brink of the falls before they were pulled to safety, CNN affiliate WGRZ-TV in Buffalo reported. The motor failed on the men's boat, and the current carried them toward the falls before rescuers were able to hook the craft with a rescue line, according to the report.