The Washington Navy Yard is returning to nearly normal operations three days after it was the scene of a mass shooting in which a gunman killed 12 people.
The Navy installation was scheduled to reopen at 6am local time. Navy spokeswoman Lt Cmdr Sarah Flaherty said that it will be a regular work day, except for Building 197, where the massacre occurred, and the base gym.
She says the gym is being used as a staging area for the FBI to investigate Monday's rampage.
Former Navy reservist Aaron Alexis gunned down 12 people before being killed by police.
Law enforcement officials are still trying to determine a motive for the shooting.
Investigators are focusing on the erratic behaviour of Alexis, who law enforcement officials say was grappling with paranoia and had reported hearing voices and being followed before he launched the attack.
The Department of Veterans Affairs said the 34-year-old visited two hospitals in the weeks before the gun rampage but denied he was depressed or having thoughts of harming himself or others.
Alexis complained of insomnia during an emergency room visit in August. He was given sleep medication and advised to follow up with a doctor. He made a similar visit five days later.