A 63-year-old woman was killed by an iron frame falling from a residential block in Tsing Yi while walking outside a shopping center with her grandson yesterday.

A renovation worker, who appeared to be installing a clothes rack at a flat on the 28th floor of the block, was arrested.

The tragedy happened at about 2.30pm when the frame, about a meter long, crashed into the woman's head outside Mayfair Gardens Shopping Centre.

Police said she was taken to Yan Chai Hospital in Tsuen Wan, where she was later certified dead.

A police spokesman said the initial investigation showed the iron frame had fallen from one of the flats in the building.

A witness who was working at Mayfair Gardens said the victim was lying unconscious in a pool of blood after being hit.

First-aid administered by paramedics did not seem to work.

She said a boy in school uniform who was about eight or nine years old was standing next to the victim, crying and shouting "grandma, grandma."

The boy, who was not injured, was later seen trying to get close to his grandmother, but was stopped by police, she said.

Another witness said the child called someone, believed to be his father, who got in the ambulance with the victim.

A source said the grandmother was on the way home after picking up her grandson from school.

A working platform had been set up outside the 28th floor of Block 7 at Mayfair Gardens.

It appeared the frame fell from the working platform.

It is believed a worker was on the platform when the frame fell.

The flat had been under renovation for two weeks and is scheduled to be completed in August.

There have been several cases of falling objects killing pedestrians in the past 11 years.

On January 21, a 24-year-old woman visiting from the mainland was killed after being hit by a falling window from The Mira Hong Kong hotel in Tsim Sha Tsui.

In January 2017, a 62-year-old retired man died after being struck by falling bamboo at a construction site for The Pavilia Bay in Tsuen Wan.

Back in June 2008, a 47-year-old woman working at a beauty salon was killed after being hit by a restaurant sign that fell while she was passing by on Wan Chai Road.

charlotte.luo@singtaonewscorp.com