My dog bit a dog in our yard?

my dog was gettin into the car an the dog across the street came over to our yard my dog was not bein aggressive at all but the dog snapped at my dog an he bit him an chased him but sadly he died. my dogs are big an they have small dogs... my female didnt do anything an the pound took her too... im sure they want to put my dogs down wat do i do??? the nieghbors dogs are always runnin around.. i dont know wat to do can anyone help me???