As is appropriate for this show, everyone died, well at least everyone who we'd seen in the first episode. I wonder if the producers had ever seen the BBC sci-fi show 'Blakes 7' - the only other series I can think of that made a point of killing everyone off in the final episode.
Series finales are always interesting, things happen that would qualify as jumping the shark if they'd happened any earlier. Plenty of births, marriages, deaths and resolutions to other drawn out stories, or frequently enough dangling threads that cancelled shows leave in the hope of picking them up, which rarely happens. I remember an awful sci-fi show called 'Space: Above and Beyond' that basically put everyone a hairs breadth away from death, they're still waiting in that limbo almost a decade on.... I don't think the network is going to renew.
And then there's Babylon 5 - one of my favourites - that show had 2 final episodes. Originally there was a 5 year plan, but it looked like it would get cancelled after series 4 so they wound up the main story arc and filmed a finale. Then they got picked up by another network and had to film a new series 4 finale without much of the cast. Actually, I think sci-fi and fantasy shows are more likely to take the opportunity to play with life and death - Star Trek TNG destroys the Enterprise not once, but 3 times in 'All Good Things', Voyager's finale starts out with everyone back on earth, minus several chacters who died on the way there, but this is Star Trek - the captain travels back in time to change history and bring everyone home alive. The X-Files brings back all sorts of dead characters, and kills them again....