The incident happened as the four-month-old little girl was being pushed in her pram by her grandmother.
CCTV camera footage shows the woman leaving the block of flats with the baby in her pram and pushing her along a footpath.
Suddenly, an icicle falls from the sky and lands in the pram where it hit the little girl in the head.
The grandmother, whose name has not been released, dashed to check on her granddaughter.
The baby, who has also not been identified, was rushed to a nearby hospital where doctors are treating her for a fractured skull and concussion.
The incident occurred in the city of Novosibirsk in south-central Russia’s Novosibirsk Oblast region.
Local police spokesman Alexey Maksimenko revealed that doctors had managed to stabilise the girl’s condition but she was still said to be critical.
Police are investigating the incident and the building’s maintenance company is facing possible charges of negligence for failing to clear the roof of ice.
The CCTV footage has gone viral after being uploaded to social media and video-sharing websites.
Netizen ‘Zinaida’ commented: “Poor thing, she might be damaged for life.”
Novosibirsk is Russia’s third biggest city after Moscow and St Petersburg, and it is regarded as the capital of Siberia.