At least three people were killed and 17 more were trapped when a half-built subway tunnel in the eastern Chinese city of Hangzhou collapsed, leaving a huge crater that also engulfed 11 vehicles, state media said on Sunday. Workers building the new metro system scrambled to escape the slow cave-in on Saturday. "Lots of workers immediately rushed to the hoist to be lifted above ground," said Zhu Juzhong, a 56-year-old worker from southwestern Sichuan province who said about 30 of his colleagues made it onto the lift, but three fell back down during the rush. "Some colleagues who moved slowly were buried," China's official news agency quoted him as saying. Another worker described a desperate climb up a steel cable after missing the lift because he was too far away. The cave-in began mid-afternoon and left a hole 15 metres deep and 75 metres long in a major downtown road. Vehicles including a public bus were sucked into the chasm. State media initially said more than 50 were feared trapped, but after nearly 30 people on board the bus were helped to safety only 17 people were registered as missing, state television said. Of the three dead, one was a worker and one was a taxi passenger. The third has not been identified, the report said. Rescue efforts were complicated by a nearby river which started to seep into the devastated tunnel, filling it with a flow up to five metres deep, but by midday on Sunday the site had been emptied again, state media said.