he was tough but why the flash, it killed him
I believe the flash saved his life.
The Genoveses and Luccheses had a contract out on his head. But due to his public persona and love for attention, he was always surrounded by the media and under constant FBI surveillance.
That was the main reason why the Chin and Vic/Gas couldn't whack Gotti. If Gotti stayed in the shadows, he would have been dead within a couple of years after taking over the family.