Several brands of contaminated cat, and dog foods, have been found to cause kidney failure.
This is for both hard, and soft foods.
Dog, cat deaths in U.S. prompt pet food recall

A list of all the brands affected, can be found at the FDA's website.
The top 5 links, listed under 2007, pertain to the recall.
FDA recall list

So, everybody with a cat, or dog, check your pet's food.