Energy giant struggles to contain offshore gas leak March 28, 2012 -- Updated 0857 GMT (1657 HKT) Total said nearly 240 workers were taken off the rig as the problem developed Sunday Union warns of "complete destruction" if gas cloud catches fire Energy firm Total evacuated the Elgin rig in the North Sea following a problem London (CNN) -- Energy giant Total was trying Wednesday to contain a gas leak that forced the evacuation of a well off the coast of Scotland. A union representing workers on the rig warned there was an "urgent need" to stop the leak, that sprang Sunday. "If the gas cloud somehow finds an ignition source, we could be looking at complete destruction," said RMT union official Jake Molloy. "This is an unprecedented situation and we really are in the realms of the unknown," Molloy said of the leak from the Elgin platform in the North Sea, about 150 miles (240km) east of the Scottish city of Aberdeen. Bob Crow, the RMT general secretary, said there was a "free flow of gas into into the atmosphere" from the platform. Nearly 240 workers were taken off the rig as the problem developed Sunday, Total said in a statement. "Investigations are ongoing to analyze the causes and to determine the remediation of the gas leak," the company said. Total confirmed there was a "sheen on the water in the vicinity of the platform," but said there was no indication of environmental damage. There have been no injuries, the company said. The leak has echoes of the BP Deepwater Horizon spill in the Gulf of Mexico, but there are significant differences. The Elgin is in significantly shallower water, which could make problems easier to fix -- but it is leaking gas, rather than oil. Gas is significantly easier to set alight. The North Sea was the scene of the world's worst offshore rig disaster, the Piper Alpha explosion, which killed 167 people in 1988.