A two-year-old boy was killed when a tree fell on his family's house in the Dandenong Ranges during a wild thunderstorm that also hit Melbourne on Saturday night.

The tragedy occurred when a tree collapsed on the two-storey house on View Road in The Patch at about 9pm.

Emergency services worked to free four adults and two children trapped in the house.

Police found the toddler's body after conducting a search of the house when he was unaccounted for.