Keating was one of a series of small outposts built in Afghanistan's remote regions. It was intended to connect civilians with international forces and the Afghan government and, of course, to fight the insurgency.
With so few helicopters in Afghanistan at the time, commanders decided when the outpost was built in 2006 that it needed to be near a road so it could be resupplied and to be near the local population.
But as the years passed, the insurgency strengthened, and relations between U.S. troops at COP Keating and the locals dissolved after a remote-controlled IED targeted a commander in 2008.
"I knew it was a bad spot, and I knew that previous commanders had expired there. But to sit there and dig up every little detail on it, it wasn't healthy for the guys to be exposed to that information," said Romesha, a section leader in Red Platoon.
There was good reason to feel that way. The base had been repeatedly targeted by insurgents with mortars and rocket-propelled grenades, including more than 40 times in the preceding five months, with sometimes deadly results.
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.