BARRIE -- Caution tape surrounds an area of Kempenfelt Bay that threatened to swallow up a family of five in Barrie over the weekend.

The close call happened on Sunday, roughly 45 metres from shore during the city's annual Winterfest event.

The family was standing on the ice when it gave way, sending all five into the frigid water, including a toddler.

Bystanders jumped into action, throwing dog leashes to rescue them from the bay's icy grip.

Barrie Fire Services Captain Keefer Hood calls the incident "extremely lucky. We always say no ice is safe ice, and this is an example of that."

Capt. Hood explains the family was near an open pressure crack that should have been avoided.

"Most pressure cracks push up - this particular one pushed down and formed a thin layer of ice over top of the water," he says.

The five were cold, wet and shaken up from the ordeal, but ultimately okay. They were all treated by paramedics with warming blankets and released, but Capt. Hood says many folks remained on the ice.

"I was surprised to see people close to the pressure crack after people had fallen into it," he recalls. "Kempenfelt Bay is up to about 150 to 160 feet deep. It has not been a cold winter. We have mild temperatures over the next two weeks. It's just not safe."

Fire crews were out on the ice along Lake Simcoe on Monday, checking the conditions. They remind everyone to use caution on the ice because conditions can change frequently and become dangerous quickly.