Officers say nine people were taken to hospital following a boat crash that happened north of Oshawa.
The accident happened on Lake Scugog late Saturday afternoon, when a large powerboat collided with a smaller boat.
Among those on board was a six-month-old baby. The child was thrown off the boat, trapped underneath. A bystander was able to swim out and rescue the infant while the other victims were pulled from the water.
The baby, and the other victims, are in stable condition.
Cause of the accident is under investigation.