VIRGINIA BEACH, Va. (WAVY) — Investigators with the FBI have completed their work at a municipal building more than a week after a gunman shot and killed 12 people.

A 45-member team has been working to reconstruct the scene at Building 2 at the Virginia Beach Municipal Center in the aftermath of the deadly shooting. The FBI has also been working to track every single bullet.

A spokesperson with the FBI confirmed investigators completed their work Monday morning and have left. Virginia Beach Police are still monitoring the scene.

Authorities said a worker in the city’s public utilities department opened fire at the building on May 31, killing 11 city employees and a contractor. The gunman — who city officials named only once as 40-year-old DeWayne Craddock — was killed in a gun battle with Virginia Beach Police.

The FBI said last week data used in the investigation will be analyzed to help understand how the shooting happened.

Questions including how — and why — the shooting happened have lingered in the days since May 31, as members of the community continue to heal and remember the lives of those killed.

A moment of silence was held across the city Friday evening to remember the victims. Hours earlier, Virginia Beach native Pharrell Williams visited a growing memorial at the municipal center.