FORT MEADE, Md. -- The Soldiers were unaware of the rocket-propelled grenade until it was fired at their dismounted patrol in the Iraqi city of Baiji.
But the vision of it exploding behind then-1st Sgt. Michael Grinston after it whooshed four inches over his shoulder is forever etched into his mind.
It's a grim, daily reminder for Grinston, who was sworn in as the 16th sergeant major of the Army on Aug. 9, 2019, of a lesson learned -- a painful one that now drives much of his priorities to build a more combat-ready force.
"When you get ambushed, and Soldiers are dying right there in the street, it is not the time to figure out if everybody knows what they're doing," he said. "It was a pretty tough day."
At the age of 19, the longtime artilleryman first signed up as a cannon crew member on a two-year contract.
He eventually stretched it into a 31-year career as he served in every leadership position from team leader to senior enlisted leader for Army Forces Command before his current role.
"I just focused on being the best person I could be at that time, in that job, at that place," he said in a recent interview.
Grinston grew up in Jasper, a northwestern Alabama town with roughly 14,000 people and a 30-minute drive from Birmingham along Interstate 22.
Named after Sgt. William Jasper, an American Revolutionary War hero, the town became Grinston's home when his mother moved there when he was a toddler.
He attended the local schools and took courses at a nearby community college after high school. He then transferred to Mississippi State University.
While he liked to exercise and had friends already in the Army, his first tuition bill from the university and a random call from a recruiter finally convinced him to join.
"I grew up with a single mother and we didn't have a lot of money," Grinston said. "So, when the recruiter just happened to call me, we were trying to [figure out] how we were going to pay for that education."
The education benefits helped, but as Grinston, who later earned a bachelor's degree in business administration, spent more time in the service, he was drawn to other aspects of it.
"I joined the Army for the college money, but that's not really why I stayed," he said. "I stayed because I enjoy the people and being active."
His admiration for the Army's "King of Battle" also grew as the years went on. His eyes light up when he speaks about artillery and the opportunities it offered him.
Throughout his career, he has led Soldiers in various units from light infantry, mechanized to airborne. He earned badges for jumpmaster, air assault, drill sergeant and even completed Ranger School, a rare feat for artillerymen at the time.
"I love being in artillery," he said, laughing. "I never really wanted to change. I got an opportunity to do all these different things within that field."
Six months before Grinston's artillery unit deployed to Iraq, they found out instead of firing rounds they would serve as infantrymen.
His unit, part of 1st Infantry Division's 1st Battalion, 7th Field Artillery Regiment, had just trained on advanced artillery ranges. The Soldiers now had to train outside their normal roles.
The unit was sent to Hohenfels, Germany, for a crash course on infantry tactics. The largest live-fire exercises they could conduct, though, were only at the team level.
"I tried to get in as many live fires as I could to kind of replicate what it feels like on the ground," he said, "because I knew it was going to be hard."
Just three days into the process of replacing the outgoing unit in Iraq, his Soldiers had their first big test.
Grinston heard over the radio that one of his unit's vehicles had broken down in Baiji, a strategic city due to its oil refinery, the largest in the country.
He rushed out of Forward Operating Base Summerall with a platoon to provide security. But once they got there, the stalled convoy was under attack, leaving one Soldier severely wounded.
"That was our first platoon live fire," he said. "In the middle of the town, being shot at, and a Soldier loses a foot."
About a month later, on April 9, 2004, Grinston and others were on a patrol through the city. This time, it felt strangely quiet. The market was closed; the streets were deserted.
It was still early in the Iraq War, and the artillerymen were unsure what it all meant.
"It's as clear as day when I run it in my mind [now]," he said. "But at the time you're going from artillery and not noticing these things."
A report then came down that insurgents were preparing to ambush the mayor's office. Grinston joined a squad-sized dismounted patrol as they headed over to investigate.
"Unfortunately, we found it," he said of the ambush.
As the patrol turned into an alley, an insurgent in a building about 100 meters away aimed an RPG at them. The Soldiers had no idea what was about to happen.
"You can't see every window," Grinston said. "If you just stand in the city and somebody wanted to shoot you, could you stop them? It's damn near impossible."
The explosion instantly killed the squad leader and platoon sergeant: Staff Sgts. Raymond Jones and Toby Mallett, respectively. Spc. Peter Enos, a combat medic, would later die from his wounds. Two others were also wounded.
Grinston walked away unscathed.
"Every day I think about that. It's what makes me wake up in the morning," he said. "When you go through something like that, it's life-changing."
Amid the chaos, Grinston and others transported the wounded and dead back to the base. There, he refitted and returned to the city with M1 Abrams tanks and Bradley Fighting Vehicles to confront the insurgents.
After hours of firefights and RPG attacks, quiet was restored to the city.
For his efforts, Grinston earned a Bronze Star with Valor device -- the first of two he would earn in his career.
The most difficult thing he has ever had to do in his life, though, did not occur against an enemy. It was calling the family members of those who would not come home.
The squad leader, he said, had to deploy late so he could watch the birth of his son. It was the first and last time he would see his son in person.
"You can't forget it, when you call that family and you have to explain that you didn't protect their husband," Grinston said, choking up. "If that's not enough motivation, then I don't know what is."
MASTERING THE FUNDAMENTALS
The fatal RPG attack, and many other combat situations he faced, continue to drive him to ensure the next Soldier is ready for them.
As the top enlisted leader in the Army, one of his priorities will be for Soldiers to master the fundamentals -- the basic individual combat tasks and skills they should all know.
"I truly believe we have to be experts as Soldiers, no matter what your [military occupational specialty] is," he said.
He will also concentrate on building more effective squads as well as taking care of Soldiers and their families.
"As a sergeant major, you're always focused in on people and people matter," he said.
As for the fundamentals, Grinston was an early proponent for the Expert Soldier Badge, which the Army recently approved.
Similar to the Expert Infantryman Badge and Expert Field Medical Badge, the new badge will test Soldiers from other MOSs on combat skills as an incentive to build readiness across the force.
During a firefight, an infantryman with an M240B machine gun, for instance, may go down and a Soldier from a non-combat arms job would then need to step up.
"You're going to feel more confident that if there's something that could happen, you know how to operate an M240," he said. "That's what it means to be an expert."
While at FORSCOM, Grinston played a key role in the development of training and preparing combat units to deploy around the world.
Former Sgt. Maj. of the Army Daniel Dailey, who had served in the position since January 2015, said the Army picked the right person to succeed him.
"He possesses all of the character and leadership qualities necessary to lead our NCO Corps into the future," he said, "and he will continue to serve the best interests of our Soldiers, their families and the Army."
Army Chief of Staff Gen. Mark A. Milley called Grinston a "world-class leader" who has deployed three times to Iraq and twice to Afghanistan as well as Desert Storm and Kosovo.
"He is the right noncommissioned officer to lead our Army into the future," the general said.
In his new role, Grinston looks to mold Soldiers to be dominant in a future battlefield, which is predicted to involve multi-domain operations against a near-peer adversary.
This is vastly different from the counterinsurgency missions the Army has grown used to and will require Soldiers to be more agile.
He looks forward to the Army Combat Fitness Test, which is set to roll out in late 2020, that he said will help Soldiers meet the physical demands of future missions.
No matter the battlefield, he added, mastering the fundamentals to prepare for it is the ultimate goal.
"The Army has been changing since the Army has been in existence," Grinston said. "We're going to make sure that we are ready and lethal for whatever we've been asked to do."