George W. Bush has returned to the Hurricane Katrina disaster zone, as a new storm threatens to wreak havoc in the devastated city of New Orleans. On his fifth visit to the storm-struck region, the US president was briefed on the threat posed by Hurricane Rita.Fears of a fresh battering have forced Mayor Ray Nagin to suspend his plans to repopulate New Orleans. Just as residents were returning to what is left of their homes, the city is once again bracing itself for the worst. The mayor fears pumping stations will not be able to cope with yet more rain. It is thought Rita could strike Texas by the weekend, where many of Katrina’s victims have taken refuge. But New Orleans could also be hit, with the possibility of significant flooding.