Philadelphia, PA (WPVI) -- It was a scary scene at Philadelphia International Airport Sunday morning after a gun accidentally went off.

Airport security spotted the .38 caliber gun in a flight attendant's carry-on when it was being screened by an X-ray machine.

A Philadelphia police officer was unloading the gun when it went off.

No one was hurt.

Philadelphia police say they are launching an investigation into the officer's handling of the gun.

As for the flight attendant, she said she forgot the gun was in her bag. 

According to the TSA's website, passengers are not allowed to carry guns in carry-ons.  Some airlines, however, do allow them to be packed in checked luggage as long as they are unloaded.

WPVI