If they weren't out of range, they weren't dying fast enough to not get to the caravan/stairs (no injuries at the time). It took some time to kill them even with all the guys out. Might have had better armour or something, not sure... never faced bowgoblins before. They were on floor two like you said, yeah.
The goblins never go in through the gatehouse, though, they go in via the underground depot instead, every time. Next set of immigrants it would probably be worth setting up a second tower with a few extra crossbows stationed there as a fifth squad (along with a DK II to fill in the vacancy left in the original DK's squad). No migrants this time around, though. Like buses, they are. 18 at once, then none, then none.
EDIT: You have a bear and a wolf in there, too. xDD How'd you do that?
EDIT: All the dwarves are leaving items in DK's grave. Mass mourning in Towntwinkles.
