Chinese Premier Wen Jiabao promised Thursday a complete and open investigation into the nation's deadliest train accident since 2008, saying anyone found to have been at fault will be punished severely.
Mr. Wen also said the government's top priority is to protect peoples' lives during a visit Thursday to the site of Saturday's train wreck, which killed 39 people and injured almost 200.
Earlier Thursday, railway officials said the crash was caused by a severe flaw in the design of signaling equipment which prevented a green light from turning to red after a lightning strike halted a train on a high-speed line south of Shanghai. That caused a second train to smash into the rear of the first, toppling several carriages off of a bridge.
The officials also said dispatchers at a station in Wenzhou should have intervened manually after the Chinese-made signaling equipment failed.
Chinese websites and newspapers have carried unusually harsh criticism of the nation's railway officials since the accident, blaming it in part on the breakneck pace of China's industrial development.
More than 100 relatives of the victims gathered at the railway station in Wenzhou on Wednesday to demand an explanation for the accident. Stung by the criticism, the government has ordered a two-month safety campaign for the rail system and launched an intensive investigation. Three rail officials have already been fired.
Internet users exploded in outrage when it was revealed that authorities had buried some of the wreckage at the scene of the crash, rather than removing it for examination. Officials said it was done to facilitate rescue efforts.
There were also complaints that authorities were too quick to call off the search for survivors. A two-year-old girl was found alive hours after the search was ordered to be ended.