A 30-year-old woman was killed after being stuck and swallowed by an escalator in a shopping mall in Jingzhou, central China's Hubei Province on Sunday and she managed to hand her toddler son, aged 2, to safety the last second before she was taken by death.

Fire fighters spent four hours cutting open the facility at the Anliang department store to set free the woman. But she was already dead when her body was pulled out. The victim, Liang Liujuan, was a full-time mom.

A seconds-long security camera footage of the incident posted online shocked the public and stirred up heated discussion over escalator safety. It showed the victim was holding her son in front of her as they went up the stairway, being the only passengers on the ascending escalator when the accident took place around 10am yesterday. Several female mall attendants were waiting on the end of the escalator as they approached the upper floor.

The mother then lifted up her son and pushed him forward as a nearby shop assistant dragged him to safety. Nearly at the same moment, the panel she stepped on collapsed. The woman's lower body was immediately stuck by the running escalator. The escalator continued rolling, and several seconds later she was seen disappearing downwards into the mechanism, despite one of the staff briefly grabbing her hand.

The woman's sister-in-law, who identified herself as kkcake, said on Weibo, that the victim was shopping with her son and husband before the tragedy. The husband was waiting on the entrance of the facility on the sixth-floor as his wife decided to take the son to an upper floor for a tour.

Some screws on the panel on the upper floor on the end of the escalator were missing and the mall management had put a warning post on the entrance of the running escalator on the sixth floor, telling people not to ride it, local media reported. Why the mother still walked onto the escalator despite the warning was unclear at present.

Her sister-in-law, who had been calling for help and attention from public during the hours-long rescue on Weibo, said the attendants gathered at the end of the escalator to inform the victim that the panel on the end was loose and dangerous.

"But the warning from the store attendants was already too late. It's impossible for a mom travelling with a kid to walk back on an ascending escalator," the sister-in-law said on Weibo.

The relatives of the victim and some Netizens were now questioning why the mall management allowed an escalator with major safety loophole to continue running with only a warning post prepared near the entrance, which was easy to miss.

The local authority is investigating the accident.

Maintenance had just been carried out on the escalator, and workers forgot to screw the access cover back into place, Wuhan Evening News cited an unnamed source as saying.

The accident was one of the top topics on China's Twitter-like Sina Weibo on Monday with more than 6.6 million views.