Police say officers responded to reports of a woman screaming at a hotel on Douglas Street at around 4 a.m. Saturday.
Officers entered the room to find a distraught woman, a young child and a toddler without vital signs.
Police say despite lengthy life-saving attempts by officers, firefighters and paramedics, the child was pronounced dead at the scene.
The mother and other child are receiving medical attention.
The B.C. Coroners Service and the Vancouver Island Integrated Major Crime Unit are also investigating the cause of death.