Why did they die? And how could I help?

Question
Hey I was wondering if you could help me figure out why my two rabbits died and what should I do to help save the rabbit when i sense a rabbit is going to die. Should i give them water? or food? Please tell me. I'm really curious and hope that I didn't do anything wrong. Well it was just yesterday I bought them from a family relative, a brown male and a white female, both two months old. They were put in a box with "water-grass" and water. I put them in the car and then took off to go home. When I reached home and looked in the box, the male was already dead laying on his side and the female still had a little life in her. She looked as if she was gasping for breath. She died soon after. Was the music in the car too loud? could that be the cause of the death? The main reason i bought the rabbits was because the people who formally had the rabbits was a bit rough with them, and i saw that the rabbits fell a couple of times during there time with the former owner. So PLEASE tell me whats the cause of the death, i really hope i'm not the blame for this.

Thanks,
Sam

Answer
hi sam -it could have been the stress of moving and the music but i doubt it.
dont know what water grass is but it may have been sprayed with insectides that are poisinous.did you have air holes in the box?
they may have been injured during the time with the previous owners its hard to say .
dave.