Contact the airline ASAP and the service center. Always try if possible to back up the photos somehow. I started to do that recently after I lost most of my first HDR shots of Krakow when one of my drives failed (was able to restore some of them). I love Picasa (comes also with a gmail account and its free like Flickr). I usually back up there my already edited JPG, on a DVD the original RAW, and usually leave the photos on my hard drive of the RAW and the edited ones.