Show me one picture of a bomb that has lights on it. Do Terrorists wearing bomb belts stroll through Isreali checkpoints with flashing LEDs "Bomb here, bomb here"
Don't be stupid. Bombs don't EVER, EVER, EVER have lights on them advertising themselves. Not once, not ever. It only happens in the movies.
Once upon a time, people thought that no one would ever fly a jetliner into a skyscraper.