US Airways has grounded the pilot whose gun discharged accidentally during a flight from Denver to Charlotte over the weekend — the first time a weapon has been discharged aboard a plane in the five years since crew members have been allowed to carry guns.

Airline and federal officials remained tight-lipped, however, about many of the details surrounding the incident, including what the damage was to the plane, where the bullet struck, and why the gun fired.

The Transportation Security Administration, which runs the program that allows some crew members to carry weapons, is investigating.

Read the full story at Charlotte.com.