An hour after Marine mortars pounded a complex of caves outside Khe Sahn, 1st Lt. Philip Howard Sauer and four fellow Marines began to scrabble toward the crest of Hill 861.

It was an unusual patrol that neared a wall of bamboo around 11 a.m. on April 24, 1967, even by the standards of the brutal Vietnam War.

The 25-year-old Sauer, a Coronado native, commanded 2nd Platoon, A Company of the 3rd Anti-Tank Battalion. Two grunts borrowed from 1st Battalion, 9th Marines and a two-man artillery forward observer team rounded out the hastily-assembled crew. So three different battalions were represented in a five-man patrol.

The idea of Lt. Thomas G. King, the mortar section commander, was for them to climb to a higher elevation to get a better look at the cave complex, which he suspected brimmed with North Vietnamese troops.

Instead, up to 30 enemy troops were dug in behind the bamboo, and they ambushed the patrol with grenades and machine gun and rifle fire.

The point man died immediately on the trail. Sauer and Private 1st Class William Marks dove into a hole.

Armed only with his .45 caliber pistol, Sauer screamed at his troops to retreat and blazed away at the North Vietnamese, covering them, pistol against machine guns.

Only Marks made it back to their lines alive.

Their moments of agony became a footnote to a bloody campaign. The rifle company to which they were attached reported 13 killed in action that day alone. And Lt. King would die less than three months later.

On May 9, 1967, Sauer's family attended a funeral Mass for him at Coronado's Sacred Heart Catholic Church. His mom, Jane Winn, was a cornerstone of the community. Coronado's public library has a room with her name on it.

Sauer was buried at Fort Rosecrans National Cemetery, his grave marker noting a Purple Heart.

In the chaos of Khe Sahn, a planned posthumous valor award never percolated up the chain of command.

Despite a Stars and Stripes story about his heroism on Hill 861, Sauer was largely forgotten by the Marines and the larger public for nearly a half-century.

That all changed when retired Marine Corps Lt. Col. David Little ran into Tom Sauer in early 2015 along the La Jolla Cove.

A West Point grad who joined the Marines, Little did two tours in Vietnam near or in Danang as an infantry officer. When Tom Sauer, a fellow ocean swimmer, told him about his brother, Little asked him what he did now -- and learned that he'd died in Vietnam.

Curious about Philip Sauer's time in the service, Little began climbing a hill of paper. He read through the "green books," unit histories from the Vietnam War, and found a paragraph describing the brief but tragic skirmish on Hill 861.

Little knew that Sauer's heroism deserved to be recognized with a valor award. He didn't realize it was going to take him nearly two years to get it.

"The focus of any story should be about Lt Sauer's bravery and the sacrifice of his family, but there's a second story that I'm not sure I want to get into and that's how we worked to get him the award he deserved," Little told The San Diego Union-Tribune in a telephone interview.

During a special Tuesday morning ceremony at the 1st Marine Division's command post on Camp Pendleton, Maj. Gen. Eric Smith will present to Sauer's siblings a Silver Star medal awarded posthumously to their brother.

It's the third-highest medal for personal battlefield bravery but it never would have gone to Sauer if it hadn't been for Little, U.S. Rep. Scott Peters, a string of Marine leaders and Secretary of the Navy Richard V. Spencer, also a former Marine.

Plus a little luck.

For the valor award to have any hope, by regulation Little had to find not only the patrol's sole survivor, William Marks, but also someone in Sauer's chain of command who could endorse the paperwork.

Online, he located retired Lt. Col. Barclay Hastings, Sauer's company commander in Vietnam, and traced him to Columbus, Ohio. Hastings was proud to recommend him.

Armed with that and a sworn statement from lone survivor Marks -- plus nine months of research culling records from the National Archives, Marine documents, oral interviews and the Stars and Stripes article -- in early 2016 Little sent the 25-page dossier to Marine Corps headquarters.

Because more then two years had passed since Sauer earned the medal, the package needed the signature of an elected federal lawmaker. So Little turned to Rep. Scott Peters, D-San Diego, a member of the powerful House Armed Services Committee.

"It's always an honor to help a San Diego hero get the recognition they earned through their service. Lt. Sauer made the ultimate sacrifice for his country and while it can never fully repay them, this medal honors Lt. Sauer's service and his family's sacrifice on behalf of our great nation," Peters said in an email to the Union-Tribune. "My office is able to help San Diego service members, veterans, and their families obtain medals, military records and benefits they earned, and I encourage anyone to reach out if they need help."

Little swam with Tom Sauer at the cove nearly every day but never whispered a word about the paper chase or the help of a Congressman.

"I did not tell the family of this submission until late in 2017 because I was never certain that anything would materialize. I finally told them when the Secretary of the Navy's office asked for family contact information," Little said.

Sauer will be memorialized 51 years to the day he died in an outdoor commemoration. Much of Smith's division staff and the band will be there, and he's sent an open invitation to all other troops under his command to attend.

"What I love about this is that it reinforces something we believe in. It's never too late to do the right thing. It was the easiest decision I've made in my eight months commanding 1st Marine Division," Smith said.

Smith hasn't finished his speech yet, but expects Sauer's Silver Star citation will help guide his pen.

"Lt Sauer knew what he was doing that day. He knew what was going to happen to him," Smith said. "He gave his life for a chance that his Marines might live. How can you not be affected by that? How can you not celebrate that bravery? It's everything we say we believe in. And we do."