A woman in her twenties has died and a man is still missing after the pair entered the waters of the Niagara River on Sunday.

Emergency crews were called to the Niagara Glen in the area of Niagara Parkway near Whirlpool Rd. around 5 p.m. after receiving 911 calls about persons in distress in the water.

Police say a group of friends from the Greater Toronto Area had gone for a hike on the trails in the gorge along the Niagara River.

They say a woman and a man in their twenties entered the water when the woman began having trouble in the current. The man tried to help her but he disappeared into the water.

Police arrived on scene and located the woman still in the water in critical condition.

“Officers pulled her from the water and commenced resuscitative efforts,” said Niagara police in a news release. “With the assistance of the Niagara Jet Boats the female was transported to the docks in Queenston.”

Paramedics and fire crews continued life-saving efforts and the woman was transported to hospital where she later died.

Officers from the Niagara Police Parks High Angle River Team, the Niagara police marine unit, the United States Coast Guard, the Canadian Coast Guard, and Niagara Jet Boats conducted vessel-based and shoreline searches for the man.

Police say he has not been located and the marine unit will continue with a shoreline search Monday morning.

The investigation into the circumstance of the incident remains under investigation.

Anyone with information about this incident is asked to contact police at 905-688-4111, ext. 1022200.