cockatiel dead randomly

Hey all, bare with me bit of a long post. i Have 2 cockatiels, both male, one about 12-18 month (Mario) and the other less then a year old (Luigi) I have owned Mario for coming up to a year and Luigi 4 month, both bought from pet shops, different ones. I have just found Mario dead on the...

Hey all, bare with me bit of a long post. i Have 2 cockatiels, both male, one about 12-18 month (Mario) and the other less then a year old (Luigi) I have owned Mario for coming up to a year and Luigi 4 month, both bought from pet shops, different ones. I have just found Mario dead on the...