Here's a tip on gun safety: If you're going to shoot someone and then flee the scene--and I don't recommend it--but if you're going to do it, make sure you wear a belt.

A 28-year old Bronx man didn't have the chance to learn that lesson.

It all started when he shot and killed a 32-year old man with whom he had been having an argument over drugs. The 32-year old's roommate poked his head out of his room to see what was going on, and our suspect took a potshot at him, grazing his cheek.

Then the suspect fled.

But then an everyday hero came out of nowhere and took him out: a pair of pants.

The suspect's drooping trousers tangled around his legs in the stairwell. And with his finger still on the trigger he fell, the weapon discharged, shooting him fatally in the neck.

"It was a murder/accidental suicide," a police source said. "He shoots the guy, runs down the stairs, trips and shoots himself."

Now you know why old men wear their pants so high.

All the ones who wore them low died stupid deaths when they were young.