CRIME

Workers return to renovated Navy Yard building that was site of 2013 mass shooting

  • Security Officer Charles Pitt, center, check ID's following the reopening ceremony for the Naval Sea Systems Command’s (NAVSEA) Headquarters building at the Washington Navy Yard, Monday, Feb. 2, 2015. The building was the site of the shooting rampage on Sept. 16, 2015, during which 12 people were killed and four wounded. (AP Photo/Pablo Martinez Monsivais )

    Security Officer Charles Pitt, center, check ID's following the reopening ceremony for the Naval Sea Systems Command’s (NAVSEA) Headquarters building at the Washington Navy Yard, Monday, Feb. 2, 2015. The building was the site of the shooting rampage on Sept. 16, 2015, during which 12 people were killed and four wounded. (AP Photo/Pablo Martinez Monsivais )  (The Associated Press)

  • Joshua Humphreys Building, formerly know as building 197, is seen in the morning as Navy official gather for the reopening ceremony for the Naval Sea Systems Command’s (NAVSEA) Headquarters building at the Washington Navy Yard, Monday, Feb. 2, 2015. The building was the site of the shooting rampage on Sept. 16, 2015, during which 12 people were killed and four wounded. (AP Photo/Pablo Martinez Monsivais )

    Joshua Humphreys Building, formerly know as building 197, is seen in the morning as Navy official gather for the reopening ceremony for the Naval Sea Systems Command’s (NAVSEA) Headquarters building at the Washington Navy Yard, Monday, Feb. 2, 2015. The building was the site of the shooting rampage on Sept. 16, 2015, during which 12 people were killed and four wounded. (AP Photo/Pablo Martinez Monsivais )  (The Associated Press)

  • Members of the Navy band are seen arriving in the morning before participating in the reopening ceremony for the Naval Sea Systems Command's (NAVSEA) Headquarters building at the Washington Navy Yard, Monday, Feb. 2, 2015. The building was the site of the shooting rampage on Sept. 16, 2015, during which 12 people were killed and four wounded. (AP Photo/Pablo Martinez Monsivais )

    Members of the Navy band are seen arriving in the morning before participating in the reopening ceremony for the Naval Sea Systems Command's (NAVSEA) Headquarters building at the Washington Navy Yard, Monday, Feb. 2, 2015. The building was the site of the shooting rampage on Sept. 16, 2015, during which 12 people were killed and four wounded. (AP Photo/Pablo Martinez Monsivais )  (The Associated Press)

The Washington Navy Yard building that was the site of a mass shooting in 2013 has reopened after extensive renovations.

About 400 employees of the Naval Sea Systems Command began reporting to work at Building 197 on Monday morning.

The building has been closed since the September 2013 shooting, in which 12 people were killed and four others were injured. The gunman, Aaron Alexis, was killed by police. Alexis was a civilian contractor and former Navy reservist who suffered from mental health problems.

The Naval Sea Systems Command says the building has a new layout and appearance following the renovations, which also repaired damage from the shooting.

A total of 2,700 workers were displaced by the shooting. Workers will move back in gradually over several weeks.