Had a Terror mission in Mexico City. Things started ok, killed a couple floaters. Started moving soldiers up.
Then two chrysalids appeared in the middle of a parking lot full of tanks. Easy rocket shot for one of my heavies. Heavy takes the shot, nails the two chrysalids...and slightly grazes a tank with the blast. Said tank blows up. Said tank was the tank my assault was stationed next to. Spoiler alert, she died instantly...things quickly went downhill from there.
My support panics, and the sniper picks off one of the weakened chrysalids. The other one is still alive, and without my assault to kill it when it got too close, it managed to run straight up to my panicking support and oneshots him. Then zombies start moving in. Because my support died, both my heavies panic when their explosives are desperately needed, giving the horde enough time to close in.
Long story short, we got rushed by chrysalids, zombies, and even a cyberdisk at one point while my squad goes into a slow but steady panic spiral. Some notable last stand moments include:
1.my two heavies working together to first shred a fustercluck of two chrysalids and 4 zombies before the other heavy nuked them all with her rocket
2.some turns later my one surviving heavy going out in a blaze of glory by blasting the two zombies and a chrysalid all huddled around her with her shredder rocket. (She had 1 health left and was done for anyway.)
3.my sniper finishing off these two zombies and a chrysalid with a laspistol by herself before getting overwhelmed.
tl;dr: TPK of a six-soldier squad of some high ranking troops on the second terror mission of the campaign, all started by accidentally blowing up my assault with a tank, igniting a panic spiral.
XCOM: Enemy Unknown on classic ironman.
I had no idea those tanks could explode if you just sneezed at them. Sucks too, my assault had almost as many kills as the sniper, and was crucial to the team. She was the only assault we had in the barracks.