A five-year-old boy in Montreal has died after falling into an in-ground pool, while his older brother was seriously injured trying to save him.

Montreal police say the boys were playing near a backyard pool in the Montreal suburb of Pierrefonds, Que. on Monday evening when the younger child fell into the water. Paramedics tried to resuscitate him, but he later died in hospital following a cardiac arrest.

Police spokesperson Raphael Bergeron said the boy’s 10-year-old brother also fell into the pool while trying to rescue the younger child. He suffered serious injuries, but is expected to survive.

“Probably the other one tried to pull him out but also fell into the pool,” Bergeron told CTV Montreal. “After that, it’s still to be clarified by the investigators what exactly happened.”

Both boys were eventually pulled from the water after a concerned neighbour heard them screaming.

The boys’ names have not been released. It’s unclear whether they live at the home where the pool is located.

Since 2010, in-ground pools in Quebec have been required to be surrounded with a locking fence, but Pierrefonds is among several municipalities that don’t require homeowners to retrofit pools with the additional fencing.

Pierrefonds-Roxboro Mayor Jim Beis said the homeowners should’ve had a second fence surrounding the pool.

“Whenever we discover there’s a pool that doesn’t meet today’s requirements, we make sure the residents know of it and they have to make corrections in order to respect the current regulations,” he said.