My mother and I will not be on the 9 am flight heading to Cancun International tomorrow, because my grandmother, unexpectedly of course, suffered a major brain hemorrhage today, and is in critical condition. We booked our trip as a last minute vacation package, so by the time we decided that it would be a good idea to buy travel insurance (for cancellation, we had our medical insurance in place), it was too late to do so.
DO NOT MAKE THE MISTAKE WE DID!
DO purchase insurance - medical and cancellation/interruption coverage is what I'd recommend bare minimum. Going through this is bad enough, but being out the $3000+ we spent on a vacation we won't be taking is quite a slap in the face.