it happens. sucks but it happens. i would listen to cavanaugh and quarentine. i would also make sure you sanatize your hands every time before handling other animals. alot of things are not airborne transmitted but are transmitted through contact such as crypto. i would take the bin out bleach it, dry it, then wash it. also wouldnt hurt to bleach the rack as well if ya can. necropsy will give ya more answers then we can since we can just speculate based on the lack of eyes on experience with your situation. i wouldnt beat yourself up about it if your husbandry is on point. i had a similar situation happen where i had a litter of gaboon rhino viper crosses born and lost 18 out of 22 in the litter. and it was atributed to a bacterial thing that the mother had. now its different because they are live bearing and balls are egg bearing but i can sympathize with ya. it sucks to have an animal die but it happens