By Todd Quinones

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PHILADELPHIA (CBS) – A woman was injured when a gun discharged during rush hour at the 40th Street subway station.

Philadelphia Police say the man whose gun went off is being questioned.

According to police, the man is an armed security guard who owns the 9 millimeter handgun legally.

They say he just got off of work and was digging around in his bag and the gun went off, and he may not have realized it.

Watch as the woman on the left in the surveillance video flinches. She says she heard a boom, and then was stunned, and confused.

“I just heard the boom. I thought maybe just something hit me, I don’t know,” victim Shirley Williams said.

Williams know she is a lucky woman.

The man to her left, police identify as a security guard.

He also jumps when police say his gun went off.

He then casually walks away and boarded his train to Center City to do some shopping.

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CBS 3 was there Friday night as the security guard turned himself in to Southwest Detectives.

Investigators say he called police when he got home and after friends told him he was on the news, and he noticed a hole in his bag.

It all happened here on the eastbound SEPTA platform at 40th and Market Streets just after 3 p.m.

Police say this security guard was looking through his bag when his gun apparently goes off accidentally, the bullet then ricocheted all over the place.

“The gun discharges into a metal bench, bounces off the metal bench into the ceramic tile, off the ceramic tile through the trash can into her arm, where it grazes it and into her face,” Lt. John Walker of Philadelphia Police said.

Fortunately a little scratch on Williams’ face and a bruised arm were the worst of her injuries.

The 21-year-old holds no ill will towards the security guard.

“I’m just happy I’m ok. I really don’t care. I’m just happy I have my life to walk away with,” she said.

Williams live in Wilmington, Delaware. She was in Philadelphia Friday to watch the new Hunger Games movie with some friends.

As of right now the security guard has not been charged with any criminal wrongdoing.

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