That included in physical feats. She held a base record in her weight class for dead lifting 280 pounds. But, Mr. Fuoco said, she was also kind and tender. After this deployment, she talked about starting a family.

Her roommate and fellow Marine, Sgt. Mallory Harrison, said in a Facebook post that for their generation stories of combat deaths often felt like something from the past — tales told by elders about a war that younger Marines had missed. Deployment meant work that was often dull and quiet. Then suddenly combat came ripping back, real and raw.

“Then bad people do bad things, and all of a sudden, the peaceful float you were on turns into you going to Afghanistan & for some, never coming back,” Sergeant Harrison wrote. “It turns into your friends never coming home. There’s no way to adequately prepare for that feeling. No PowerPoint training, no class from the chaps, nothing. Nothing can prepare you.”

The service members killed in the attack, in addition to Sergeant Gee and Sergeant Rosario, include Marine Corps Staff Sgt. Darin T. Hoover, 31, of Salt Lake City; Corps Cpl. Hunter Lopez, 22, of Indio, Calif.; Corps Cpl. Daegan W. Page, 23, of Omaha; Cpl. Humberto A. Sanchez, 22, of Logansport, Ind.; Lance Cpl. David L. Espinoza, 20, of Rio Bravo, Texas; Lance Cpl. Jared M. Schmitz, 20, of St. Charles, Mo.; Lance Cpl. Rylee J. McCollum, 20, of Jackson, Wyo.; Lance Cpl. Dylan R. Merola, 20, of Rancho Cucamonga, Calif.; Lance Cpl. Kareem M. Nikoui, 20, of Norco, Calif. The dead also include the Navy Hospitalman Maxton W. Soviak, 22, of Berlin Heights, Ohio, and Army Staff Sgt. Ryan C. Knauss, 23, of Corryton, Tenn.