Around 90 workers were injured in Singapore Monday, more than 20 seriously, when a rig they were working on started to tilt, officials said, dpa reported.
One was in critical condition, and 22 were seriously injured, with the rest suffering only minor injuries, the Ministry of Manpower said.
The accident happened at Jurong Shipyard Pte Ltd, one of several Singaporean shipyards building oil and gas rigs.
The jack-up rig, so called because it is designed to raise itself on its own legs after being towed into place, tilted to one side when one of its three legs failed during a test of the jack-up mechanism, the shipyard's owner Sembcorp Marine Ltd said.
Workers told local TV station Channel NewsAsia that they were conducting welding, fitting and piping work at the time.
All work has stopped at the listing rig.