Manion, who had been buried in Pennsylvania, was reinterred Friday at Arlington National Cemetery in Virginia. Looney will be buried beside him on Monday.
It came about through the ties between the men that became ties between their grieving families.
Manion's sister, Ryan, said the men were cut from the same cloth. They weren't the loudest guys, but they had a commanding presence. They would do anything for family and friends. And they loved their country.
They graduated from the Naval Academy in 2004.
Ryan Manion said her brother, Marine Lt. Travis Manion, 26, of Doylestown, Pa., felt good about what he was doing in Iraq.
In 2007, he was killed there.
Afterward, Navy Lt. Brendan Looney told Manion's mother that he was dedicating his training to become a SEAL to Travis' memory, Janet Manion told Action News.
On Sept. 21, Looney, 29, of Owings, Md., died in a helicopter crash in Afghanistan. Within minutes of hearing the news, Manion's parents were in a car, rushing to the side of Looney's parents.
"It's a club no one wants to join," Ryan Manion said Friday. "We know what they're going through. We will be there for them and we can lean on each other."
Looney's wife, parents and siblings attended Friday's service, where they held hands with Manion's family. The same thing will happen on Monday.
Ryan Manion said that after her brother died, he was buried in the family cemetery near Philadelphia. Later, however, Ryan remembered that Travis had said he wanted to buried at Arlington. The family went back and forth, and had recently decided to have Manion moved to Arlington.
Then came the devastating news that Looney had been killed.
Looney's wife, Amy, said she wanted her husband buried next to Manion, Ryan Manion said. The two families worked together to help bring it about.
At Friday's ceremony, dozens of Marines stood in rows behind a large photograph of Manion. Because the event was a reburial, there was no 21-gun salute.
Red roses and tiny American flags were handed out. Manion's mother, Janet, escorted members of the Looney family to the side of the grave.
As mourners walked by, some knelt and prayed briefly, then tossed the roses in with the casket.
Associated Press photographer Jacquelyn Martin in Arlington, Va., contributed to this report.