Opponents say the government's policy is 'a disaster waiting to happen'. [=something that will probably have a very bad or tragic result]
The government's policy is 'a recipe for disaster'. = The government is 'flirting with disaster' by pursuing this policy.
The earthquake was one of the worst 'natural disasters' [=a disaster caused by natural forces] of this century.
(..) I know it all seems a bit much... ...but how else was I going to meet you, Superman? I knew you'd never accept an invitation to tea. But a disaster, with people in danger, people who needhelp.... I just knew you couldn't resist that chance to sort of pitch in. You know what I mean? (..)1978 Superman