A 3-year-old Toronto boy died Thursday after wandering away from an apartment building into bitterly cold weather overnight.

Police were notified of the boy's disappearance at 7:30 a.m. by family members who said they woke to find him gone and the front door open. They said they'd last seen him in his bed Wednesday night.

Security camera video showed the boy, named Elijah, leaving the building at about 4 a.m. After a massive search, he was found just after 10 a.m. in a nearby yard. He did not show any vital signs, and was rushed to the hospital. Police later announced his death on Twitter.

Temperatures dipped to as low as minus-20 C (minus-4 F) during the six hours Elijah was outdoors.