When bus driver Li Li got caught in a traffic jam under a viaduct in Zhuzhou city, Hunan Province, he advised the 10 passengers onboard to get off and walk.

An elderly couple were reluctant to leave their seats, but Li suggested they walk along a bridge and promised to pick them up when traffic resumed.

Li, 30, ended up saving his passengers' lives, when a 200-m section of the viaduct collapsed moments later on Sunday afternoon.

Li was still in his bus when the overpass - which had been closed to traffic - started falling but managed to escape unhurt.

"I saw dust falling from the viaduct, it was all over the place. So when I spotted a pillar collapsing, I jumped out of the bus," Li told China Daily yesterday.

At least nine people died and another 16 injured in the collapse at downtown Hongqi Road, Chen Jing, Party secretary of the Zhuzhou city government, told a press conference yesterday.

Eight of the injured have been discharged from hospital and of the remaining eight, none was in a critical condition, he said.

The disaster reportedly damaged about 24 vehicles including Li's bus, and some of them were totally crushed.

The bus driver himself was awarded 10,000 yuan (US$1,460) by his company for saving the lives of his passengers, whose brush with death has been described by locals as "a miracle".

Zhang Chunxian, Hunan's Party chief, has ordered a thorough investigation into the cause of the collapse and full information disclosure to the public.

More than 550 people were involved in rescue operations. Three life detection devices were used to search for anyone buried in the debris, and 30 excavators to clear the rubble, Chen said.

The Zhuzhou government had earlier planned for the viaduct - which was said to be in perfect condition - to be demolished tomorrow because it spanned the bustling Hongqi Square and caused severe traffic congestion in the area. The overpass, which came into use in 1995, is said to be the first urban flyover in Hunan. It was 2.75 km long and 8 m tall.

Workers had blasted part of the viaduct last Friday to test the amount of dynamite needed for imploding the entire stretch. The collapsed part was close to where the test explosion took place.

Cracks had earlier been found on nearby sections of the viaduct after the test, Caijing magazine quoted witnesses as saying.

Municipal authorities refused to comment on the cracks, saying the cause of the collapse was under investigation.

"If a test blast was found to have damaged the bridge earlier, stricter measures should have been taken to control the traffic under the bridge," said Wu Dingjun, a professor with Tongji University's department of bridge engineering in Shanghai.

The municipal public security bureau said police have detained people suspected of being responsible for the collapse, without giving details. The State work safety agency has also assigned a senior officer to the investigation.

Hunan Governor Zhou Qiang ordered an inspection of all viaducts in the province to check for hidden dangers, the Zhuzhou government said on its website.

(China Daily May 19, 2009)