Why wasnt a kill switch put in after adam pettys acident?

May be...

why did kenny irwin have to die to in almost the exact same spot? is their some part of the story im missing?

2 Kill switches are and have been if Race Cars for Many Years!!!!!!!!--1 on the Dash and 1 on the wheel. When you are fighting for control of the car you dont have time to use it. They are mainly used after impact to shut the Engine Off to Prevent Fires!!!!!!!

Yep, you're missing a big part of the story....that they have multiple kill switches....including one on the wheel drivers will sometimes accidentally hit and kill the motor, lol.