Witnesses describe the chaotic scene at the Washington Navy Yard on Monday morning, where at least one gunman opened fire and the death toll rose to more than a dozen. (The Washington Post)

Some heard a burst of shots as they went about their morning routines. Others were startled by fire alarms but thought it was just a drill. Many were still commuting to the Washington Navy Yard when they received e-mails and alerts telling them to stay away.

Some employees locked themselves in offices and closets for hours, waiting for rescue without much food and with spotty cellphone reception. Others fled their buildings, gathering in a drizzling rain to share their experiences and try to piece together what had happened.

Tim Jirus, a U.S. Navy commander, was working on the fourth floor of Building 197 when he heard two or three shots. It was distant, and he couldn’t tell if it was real.

Suddenly, people ran through the cubicles, shouting, “Get out!” The fire alarm went off. Jirus said he remained calm and joined colleagues who were filing out of the building. Outside, he saw a co-worker being loaded into a police car. He was told by colleagues that the man had been shot. Then he heard more shots.

Jirus thought he would be safe in an alley next to his building, where he hid and talked with a civilian about what was unfolding. Then came the sound of two more gunshots — very loud and echoing through the alley. Jirus looked toward the direction of the sound, then looked down: The other man had fallen to the ground, shot in the head, and apparently dead.

Jirus said he didn’t know whether the shooter was on the roof or if he could find an open door. He ran, seeing security officers arrive at the end of the alley and shelter behind police cars. He was terrified.

“I was running for my life,” said Jirus, 48, who lives in the Dupont Circle area.

He sprinted behind a maintenance building and quickly scaled a tall black metal fence, avoiding the spikes at the top. He kept going.

“I was just lucky,” he said. “There were two shots. He got that guy. He didn’t get me.”

Patricia Ward, a Navy logistics management specialist, said that she was at an ATM machine in the first floor atrium of Building 197, home to the Naval Sea Systems Command, when she heard loud, short explosions coming from a few floors above the open lobby. She and her two companions, who were on their way to breakfast, exchanged glances.

One of Ward’s friends started to ask: “Was that a gunshot?” But she was interrupted by the sounds of “BAM BAM BAM BAM BAM,” Ward said.

“We knew it then,” Ward said. “We just started running.”

(The Washington Post)

A security guard on the sidewalk, her gun drawn, told them to keep running. Five blocks away, Ward waited in the drizzle for news of her co-workers. She called her manager, who told her to make her way home to Woodbridge, even though her purse, phone and other belongings were still at her desk.

The sound of gunfire was a foreign sound on a Monday morning. One Navy Yard employee said it sounded like “a guy dropping a wooden pallet.” Another described it as “someone dropping an old metal desk.”

Then came the fire alarms. The panic. The evacuation or sheltering in place. Warning e-mails. Helicopters overhead. Police everywhere. Sirens and lights flashing.

Paul Desbiens, a Navy contractor, said that when the fire alarm went off about 8:30 a.m., he and other employees thought it was a fire drill. When they got to the building’s entrance, they encountered police.

“They didn’t say what was going on,” Desbiens said. “They just said, ‘Run!’ ”

Those who got away gathered near the Navy Yard entrance in drizzling rain, unsure of what to do. A few complained about what they consider a lack of security.

“How can a military installation allow a . . . gunman on base?” one man said.

Dewey Carpenter was locked down in Building 210, which is across from Building 197, where the shootings occurred. A garbled loudspeaker announcement told employees in several Navy Yard buildings to “take shelter.” A later e-mail echoed those instructions and told them to stay away from windows.

“The mood is solemn, concerned,” he said. “Some people are really scared. . . . Everyone in here knows somebody next door.

And then came the hours and hours of waiting. As news of the shooting spread, people tried desperately to reach family members and friends who work in the area, but it was difficult to get cellphone reception.

U.S. Air Force Tech Sgt. David Reyes said his wife, Dina, was locked down all day — at her desk, hungry and worried about her friends. He received a text from Dina, a civilian who works in human resources for the Navy, at 8:30 a.m. to say there was a shooter on the Navy Yard campus.

They exchanged texts until 10 a.m., when he lost contact with her. Worried, he headed to the campus from Andrews Air Force Base to see if he could locate her. They managed to make contact again via text and he found out she was okay.

Others flocked to a parking lot near Nationals stadium, the designated meet-up point.

Jacqueline Alston, a 63-year-old usher at Nationals stadium, was waiting to hear from her common-law husband of 18 years, Ernest Johnston, who works as a custodian on the fourth floor of Building 197. Around lunchtime, she still hadn’t heard from him, pleading: “Come home!”

Carol Holsey was looking for her sister, who works for the Department of Defense and has to turn in her cellphone to security each day because it has a camera on it. Holsey’s phone started ringing incessantly Monday morning with the news. On her way to the stadium, she was so distracted that she got off at the wrong Metro stop.

“This is so crazy, “ said Holsey, a retired government worker who lives in Temple Hills. “That place has so many buildings it is impossible to know if she’s okay.”

As a lockdown was lifted about 3 p.m. at a building holding Department of Transportation employees, employees rushed out. Wilma Glover was one of hundreds headed toward the Navy Yard Metro station.

She described the day as “nervous, frantic” as employees checked the news for updates on the shooting and supervisors came around doling out information about the lockdown.

“I’m happy” that it’s over, said Glover, who lives in Forestville. “I want to go home.”

Michelle Boorstein, Justin Jouvenal, Luz Lazo, Robert Samuels, Nikita Stewart and Steve Vogel and contributed to this report.