1 dead, 1 injured after boating incident on St. Lawrence River near Brockville, Ont.

Ontario Provincial Police say one person is dead after a boat capsized on the St. Lawrence River.

The incident, which police initially described as a "marine collision", happened Saturday at around 8 a.m. near Butternut Bay, west of Brockville, Ont. OPP, RCMP and Brockville police all attended the scene.

Police were called because a boat had flipped over in the water.

Two people were in the vessel. A 64-year-old from Leeds and the Thousand Islands Township was pronounced dead at the scene. A second person was taken to hospital; their condition is unknown.

The deceased has not been identified.

"There was an ambulance, police and fire. Several different kinds of sirens going at once," said Darlene Francis, who heard the sirens Saturday morning. "Never did I think it was coming from the river, though."

A witness who declined to be identified told CTV News first responders brought the victim to the Brockville boat launch and performed CPR. Neighbours say at least one area resident helped with the rescue.

"A fatality in this area. That’s the first one I’ve heard of," Francis said.

OPP are reminding boaters to check safety equipment before heading out on the water, including personal floatation devices, and to be aware of local conditions.

The incident remains under investigation. Witnesses are asked to contact the OPP's Leeds detachment at 1-888-310-1122.

• The information you need to know, sent directly to you: Download the CTV News App

--With files from CTV News Ottawa's Natalie van Rooy.