01/30/2015 11:51 EST | Updated 04/01/2015 05:59 EDT

Drummondville fire claims lives of 2 boys, ages 4 and 7

A fire in an apartment building in Drummondville has claimed the lives of two boys, aged four and seven.

The boys' mother, who is in her 30s, and a newborn who is only a few days old were intoxicated by the smoke and rushed to hospital in critical condition.

The Sûreté du Québec said the fire started around 6:30 p.m. on the second floor of a four-unit apartment building on des Écoles Street.

Investigators are on the scene trying to determine the cause of the fire.