Just hours after Bravo Troop arrived in May 2009 at the outpost, the soldiers they were replacing came under fire as they were leaving -- with one suffering a massive head wound and others suffering shrapnel wounds.
These insurgents weren't "your average run-and-gun types," Romesha said later.
He knew it wasn't a question of would they be hit, but when.
Explosions and gunfire
Romesha, Sgt. Thomas "Raz" Rasmussen and the other soldiers of Bravo Troop spent countless hours plotting what a Taliban strike at Keating would look like.
Would it come under the cover of darkness when the soldiers were asleep? Would they take out the mortar pit first? Would they target the Humvees positioned throughout the base to spot insurgents taking potshots? Would they target the ammunition depot?
The answer came just before sunrise on October 3, 2009.
It began with the sound of explosions and gunfire right outside the base.
Pfc. Chris Jones was awakened by the explosion. He grabbed his machine gun and headed out the door.
Romesha, "Ro" to his fellow soldiers, heard it too. As he put on his body armor, he listened to reports coming in over the radio.
"You could just tell this was something serious," he said.
Much of the base's defense relied on a mortar pit to target high, angled positions where the Taliban would take cover and fire, and a nearby Humvee equipped with a long-range surveillance system. Both were set up on the opposite side of the base.
There also were some 20 soldiers at an observation post on the side of a nearby mountain that looked down over the base and could provide covering fire.
That morning, the Taliban began the attack by focusing their fire on the mortar pit, the Humvee and the observation post.
In the first minutes of the battle, Pvt. Kevin Thomson was killed -- gunned down as he ran for the M240, a belt-fed, gas-operated, fully automatic machine gun.
From that moment, manning the mortars was impossible for Bravo Troop.
For years, the Taliban had been testing COP Keating's defenses, one attack at a time.
They studied the base's perimeters from various positions on the mountain, high above the base.
It was clear, almost immediately, that this was a well-coordinated attack and it had been launched by more than just a handful of insurgents.
What the soldiers didn't know was that the Taliban had hidden mortars, rockets and heavy machine guns in the mountains around the base. The soldiers couldn't see the hundreds of militants who had taken up positions around them.
Among them were Taliban snipers who picked off soldiers in the base below.
Sgt. Joshua Kirk was killed while returning fire; Spec. Michael Scusa was gunned down as he ran to deliver ammunition.
Amid the explosions and gunfire, Romesha was trying to organize and rally his soldiers.
"The shots just kept coming in and coming in and coming in," Jones said. "I could barely hear myself think. I mean everywhere around me was being hit."