Photo taken on June 27, 2009 shows the scene of a toppled building in Shanghai, China. A 13-storey building under construction in the "lotus riverside" neighborhood of Minhang district fell down entirely early Saturday morning. The accident killed one person. The cause of the accident is under investigation. [Photo: Xinhua]

A 13-floor residential building under construction in Shanghai's Minhang District toppled over almost intact Saturday morning, killing one worker.

The man, surnamed Xiao and aged 28, had gone into the unfinished complex to get his tools and tried to jump out the window when the building fell in "Lotus Riverside" residential community.

Police cordoned off the area and all workers were evacuated.

About 132 households in the vicinity were evacuated, with 120 families going to hotels paid by the district government and the rest making their own arrangements.

The cause of the collapse was still under investigation late last night.

No indication of further listing has been detected in seven other buildings in the compound and foundations were confirmed as secure when checked at 6pm on Saturday.

The collapse occurred at about 5:40am when most nearby residents were asleep.

Four workers were on duty in the building before it toppled. Three escaped but the last one, Xiao, from Anhui Province, was buried and died before medical help arrived. His colleagues said he was caught collecting his tools.

The collapsed building was situated less than 30 meters from the bank of Dianpu Creek on a landfill area that previously had been subjected to silt buildup.

On Friday, a Minhang TV news channel reported the collapse of about 83 meters of the river bank, believed to have been caused by the weight of dumped earth removed from beneath the building to construct a garage.

A lot of earth from under the building was flushed into the river after the bank collapsed.

The developer and the builder organized teams to work overnight on Friday moving earth in order to repair the bank. "The lights of the construction site were on for the whole night and there were trucks continually transporting the mud out," said Fang Zenghui, a resident on the opposite side of the creek.

Residents were shocked by the building's collapse.

"It was very loud. I was stunned and couldn't believe what I'd just seen," said Fang who saw it fall while doing his morning exercise. "It was horrible. The building fell down very quickly after several workers ran out of it."

Owners of apartments in the compound were worried about the quality of other buildings and visited the construction site at 10am to ask for refunds on their properties.

"The developer should give us an explanation," said an owner surnamed Zhang whose old house has been demolished and lives in a rented place. "My family were waiting to move into the new home which is impossible now. They should make it up to us."

Developer Shanghai Meidu Real Estate and builder Shanghai Zhongxin Construction Co said they were contacting owners to negotiate refunds.

The average price of apartments in the collapsed building was 14,297 yuan (US$2,093) per square meter and 77 percent of the houses had been sold.