President Barack Obama has ordered US flags to be flown at half-staff to honor the victims of the December 2 shooting in San Bernardino, Calif., that left 14 people dead.

The Associated Press is reporting that President Obama signed the proclamation Thursday morning.

The brief proclamation says the gesture comes “as a mark of respect for the victims of gun violence perpetrated” on Wednesday. Flags are to be lowered immediately, and are to remain at half-staff through sunset Monday, December 7. The announcement affects flags at the White House, public buildings, military installations, US Navy ships, embassies and diplomatic missions.

Connecticut Governor Dannel P. Malloy has followed suit, ordering all US and state flags in Connecticut to fly at half-staff until sunset Monday.

Hook & Ladder firefighters lowered the flag on Main Street shortly after 1 pm Thursday.

According to the AP two people, a man and a woman, killed 14 people at a social service center late Wednesday morning before dying in a gun battle with police hours later. Another 21 people were wounded in the attacks at the social service center. 

The male shooter reportedly fired on colleagues at a holiday gathering for the Department of Public Health. The carnage happened at Inland Regional Center, which helps people with disabilities find work, get treatment, housing and transportation.

The AP is calling the December 2 shootings the nation’s deadliest mass shooting since 12/14.