(NBC News) -- Many employees at the Washington navy yard are finishing their first day back at work since Monday's shooting massacre.
The yard reopened for normal operations today, as a memorial service was held for the first of twelve victims.
Emotions are mixed, some say they need to get back to their routines to recover.
But for others coming back to the yard just three days after the tragedy is too soon.
As they filed through security gates at the yard, some saluted officers standing guard.
"its part of returning to normalcy and that is always a good thing," said one employee.
But things are far from normal.
Building 197 where 13 people died, including the shooter, is still closed.
Chad Moses spent hours barricaded inside his office on the day of the shootings.
He says he's not ready to come back.
"I was the last guy out and I could see my co-worker lying face down 25 feet away," remembered Moses. "It finally hit me Tuesday morning and its been rough every day since."
Security procedures at the yard and all military facilities are now under review.
Including how Aaron Alexis was able to get and maintain security clearance despite mental health issues and past gun related incidents.
In Maryland, the first memorial service was held for Vishnu Pandit.
He was a husband, father and grandfather who worked for the Navy for more than 25-years.
-- Danielle Leigh, NBC News reports