Cornish X questions

[ibpboo]

Pardon my ignorance. Do they always die at a young age or can they live a long life? How are there chick Cornish x if they can not survive, or is it because they are always chicks of two breeds?
I'm asking because my son came home with two cornish x's and I haven't had the heart to tell him they do not live long. Can I just feed them crumbles and let them free range during the day, or are they just doomed?

 

[danielbrown]

They are crosses from two different breeds.
To get them to live longer they need special care.
The longest I've heard of them living is around 2 years.
They get about 15lbs or more full grown.