Defenders are helpful during missions, especially when you're alone, however they need to be kind of close to the action to actual get involved (which can lead to them taking quite a bit of damage).
I'm aware that at the end of the mission, or if the defender post platform is destroyed that they give back the weapon/ammo and the defender goes back to your inventory/squad.
As also mentioned here:
" - What happens my stuff when a defender leaves the mission or the mission ends?
Any time a mission ends or the defender leaves the mission, all items and ammo will go back to the players backpack."
My question that I haven't been able to figure out is, if a defender dies, do they just go back to your inventory/squad, or do they die entirely and get removed from your inventory/squad?
I just want to know if I should be managing my defenders better to try and prohibit their deaths.