Sorry to bother you, but I'm afraid something urgent has come up

If there's a world-wide all-out nuclear war it's said that there will be a "nuclear winter" all over the planet for several months

It happened while I wasn't looking

It was an accident that was waiting to happen

He went on reading the book as if nothing had happened

He smoked as if nothing had happened

It is said that there will be a big earthquake in the near future

Nothing happened