One crew member has died and four others have been injured, two seriously, after a lifeboat accident on the world's biggest Harmony of the Seas cruise liner. <br/><br/>During a stopover in Marseille, the crew were reportedly taking part in a safety exercise when the lifeboat became detached from the fifth deck. <br/><br/>Harmony of the Seas can hold more than 8,000 passengers and crew. The Royal Caribbean ship is higher than a 25-storey building. It entered service in May this year.