BEIJING - A shocking surveillance video emerged this week out of the megacity of Chongqing, showing a 10-year old girl grabbing an infant boy in a high-rise elevator and then proceeding to slam him onto the floor and kick him repeatedly.

The baby was then found downstairs on the sidewalk alive, covered in blood but clinging to life. Authorities are now trying to determine whether the 10-year-old girl threw the infant off the 25th floor.

According to the Chongqing TV News the incident unfolded on the afternoon of Nov. 25 when a woman identified as Mrs. Wu took her grandson Yuanyuan, who is a little older than 1-year-old, out to play.

The surveillance video shows Mrs. Wu exiting the elevator with empty infant push bike just as the 10 year old girl, still in her school uniform, slips into the elevator. The girl then immediately bends down to pick up the boy as the elevator doors close on the grandmother.

Mrs. Wu later claimed to Chongqing TV News that she momentarily left the elevator to remove the push bike. Instead of handing Yuanyuan back to his grandmother, the schoolgirl held onto him as the elevator doors closed in the grandmother's face.

The girl then throws the baby on the ground and starts kicking him. The video shows Yuanyuan struggling on the floor.

When the elevator finally doors opened on the 25 th floor of the apartment building, the girl picks up baby and throws him to the floor outside the elevator. She exits as Yuanyuan is shown with his arm flailing on the floor outside.

The elevator doors then close, ending the surveillance of the girl and the infant.

Chongqing TV News reported that Mrs. Wu followed the girl up to the 25 th floor and ran into her in the hall without Yuanyuan. The girl then apparently tried to comfort the distraught grandmother and told her than someone else took the baby and proceeded to search the apartment with her, the report said.

Five minutes later, a security guard found the baby on the ground, with broken branches and twigs around puddles of blood.

According to Chongqing TV News, the Wu family had just moved to the apartment compound about a month earlier. They did not know the girl and have no idea what would motivate her to attack Yuanyuan.

Yuanyuan's family confirmed to The Beijing News that he awoke from a coma on Dec. 3. The family tells The Beijing News that Yuanyuan remains in critical condition with a broken skull and internal bleeding. A doctor told the newspaper that Yuanyuan will need a "high-risk operation" very soon.

The Chongqing police have not released any information on the attacker and her current status due to the fact that she is a minor.

Yuanyuan's family, however, told The Beijing News that the attacker's family has given them 58,000RMB ($9,515) in compensation after the accident.

The newspaper reports that both Yuanyuan's parents are construction workers and the money will not be enough cover Yuanyuan's medical expenses.

ABC News' Kaijing Xiao contributed to this report