3 Rabbit deaths in the space of 2 weeks?!

Question
Ok, so i got 2 bunnies as an Easter present.One male and one female.They loved each other and were brother and sister.
They were perfectly fine, from being babies.Infact they had 1 littler.
They had the whole garden to play in for a year, then we separated the garden into two parts and we put them in a smaller area. They were in the smaller part of the garden for about 4 days. And we found the girl rabbit dead lie ing in the garden she had no scars or marks to prove she'd been killed though. The boy rabbit was terribly sad, so we got another baby rabbit! The two didn't get along too well so they were put in different hutches (at night). anyway, 1 week after, the male wasn't eating, drinking and was dragging his back legs along, in his hutch. We immediately took the rabbit to the vets! His back legs had gone, due to thumping them when looking for his partner after she died. he had to be put to sleep. the baby rabbit was fine in the garden, until one night she was put in the males hutch at night (as he was no longer there). And in the morning she had died... she hadn't froze or anything , she wasn't bleeding, and she hadn't been frightened because her hutch had been covered up with a sheet. What happened to all my rabbits, how did each one die? And when will it be safe for me to get more bunnies in the garden? Thank you, Molly.

Answer
Hi Molly,

I am sorry to hear about your rabbits dying.  

The only way you can know what it was would be the vet to perform a necropsy on your rabbits, to determine a cause of death.  Otherwise it's just speculation.

From the little you relay to me about it, I'd say they may have died from complications of heatstroke.  For the male, a second possibility is improper handling that caused either his back muscles to tear or caused a fracture in his back.  A third possibility would be that you have some kind of predator in the backyard that (while not touching them) frightened them to death - in the case of the male caused him to injure himself being scared.

My strong suggestion to you would be to not keep rabbits outside.  Adopt from a shelter, that fixes rabbits, and keep them inside the house as indoor house bunnies.  You don't have to give them free reign of the house, but they will be safer inside, will be able to enjoy you much more and be closer to you, and be in a better climate controlled environment while still getting natural light through windows.