In early June, Buchanan sent a letter to Defense Secretary Mark Esper, demanding reforms.
Spc. Cole Jakob Aton died Aug. 12 from "injuries suffered while providing assistance at an accident scene.
Once all the caskets were aboard the C-17, a Navy chaplain aboard the plane said a final prayer.
A Marine sergeant drowned after going for a swim after a unit physical fitness event in Macon, Georgia.
The remains will be transported to Dover Air Force Base for preparation for burial.
Defense Secretary Mark Esper said that the massive explosions that devastated Beirut were most likely a tragic accident.
The scale of the damage resembles other blasts involving the chemical compound commonly used as an agricultural fertilizer.
The AAV, which sank after taking on water while training, had 16 troops aboard in total.
Officials announced early Sunday that leadership determined little likelihood the service members survived the accident.
Amphibious vehicles — commonly called "Amtracks" — have been part of the Marine Corps' fighting force since World War II.
The open letter, published Thursday morning by National Security Leaders for Biden, contains 489 names.
Families of those lost in the USS Thresher tragedy are finally getting a look at hundreds of documents about the accident.
The campaign of President Donald Trump released a letter from 235 retired senior officers backing his re-election.
The America Class amphibious assault ship was virtually commissioned July 15 at its shipyard in Pascagoula, Miss.
Three Marines and a sailor have been bitten by a coyote on the loose at Camp Lejeune.