What is your obligation as a PI?

Say you’re a PI of medium sized lab (or any size, it really doesn’t matter for this question) and you get an offer from a non-academic place to go work there. It’s very tempting because they pay tons of money, and with the difficult time getting grants that sounds like sweet music to your ears. So you take the job, which means your techs, grad students and post-docs don’t have a PI anymore. 

What is your obligation here? The grad students will be taken over by other PIs because the school promised them continuous funding (although it will cost them extra time), but what about the techs and the post-docs? Officially, of course, you probably owe them nothing (or do you?), but in reality what would you do? Do you try to make sure they get somewhere or is that not your problem?

Of course, this is an entirely hypothetical situation. I just wanted to talk about something else than the Boston Marathon bomber for a change.