A California public transit officer accidentally shot and killed a colleague Tuesday.

According to the Associated Press, authorities have said that a Bay Area Rapid Transit police officer accidentally shot and killed a fellow officer in the department’s first ever on-duty fatality.

The Washington Post reports that Sgt. Tom Smith, was shot by another officer while searching an apartment for a laptop and items that were believed to have been stolen.

Transit Police Chief Kenton Rainey did not take questions from reporters, but revealed in a news conference that seven officers were at the scene of the shooting, investigating the theft of BART property.

Prior to the conference, Chief Rainey released a joint statement with BART General Manager Grace Crunican.

“The entire BART organization is deeply saddened by this tragic event, and we ask the public to keep the officer's family in its thoughts and prayers.”

The officer who shot the 23-year veteran was not named and investigators are gathering information of how the shooting happened.