Sadly, this is the business we're in. Sh1t happens and we have to live with it - it's a prerequisite of our role.
I have been through an earthquake in Jamaica, friends of mine have spent seven days in Orlando staring down Hurricane Charlie of last year. Other crew I know were in Islamabad when the disasterous quake hit last week.
If airlines evacuated crews each time a "natural disaster" hit, not only would airlines be forever shipping crew around the world, they'd also be leaving lots of passengers stranded due to disrupted operations (i.e. plane lands from London and there's nobody there to take it back).
This way, when the worst is over, a plane can be sent right out and these guys and girls will be there to take the flight straight back with holidaymakers onboard who also survived.