24-year-old Petty Officer 3rd Class Denis Miranda of Toms River, N.J. was among the casualties.
He died when the helicopter went down on Tuesday.
"He was ecstatic he was going. It was his job, his dream job and he did it," said brother Kevin Miranda.
"He was barely there but my brother did two years worth of training to get there. He picked one of the most grueling and most difficult jobs in the military because that's what was going to give him satisfaction," said brother Alan Miranda.
The brothers say Miranda was engaged to Lacy Cromwell of Oregon, who arrived this afternoon at their house to grieve with the family.
Not far from there the flag is flying at half mast outside Toms River East High School where Denis Miranda graduated in 2003.
An excellent swimmer, his coaches describe him as a go-getter who worked hard to become an elite SEAL.
"He seemed like he had a real passion for it, he enjoyed it and I was happy for him," said coach Brian Cerbone.
Miranda worked as lifeguard at Ortley Beach, and fellow guards sent a sweatshirt to keep him warm in Afghanistan.
One former teacher remembers Denis specifically because, she says, when his class used to say the Pledge of Allegiance he stood out from all the other students.
"His hands stayed on his heart through both the Pledge of Allegiance and the national anthem and I could just tell that it really meant a lot to him," said Margi Albrecht.
Family members traveled to Dover AFB on Wednesday to be there when Miranda's body returned to the US. Funeral arrangements are incomplete.
The other victims are identified as 29-year-old Lt. Brendan Looney of Owings, Md., 30-year-old Senior Chief Petty Officer David McLendon of Thomasville, Ga. and 26-year-old Petty Officer 2nd Class Adam Smith of Hurland, Mo.
McLendon was assigned to a Naval Special Warfare unit. Looney, Smith and Miranda were assigned to SEAL teams.
Five members of the Fort Campbell, Ky.-based 101st Combat Aviation Brigade were also killed.
They are Maj. Robert F. Baldwin, 39, of Muscatine, Iowa; Chief Warrant Officer Matthew G. Wagstaff, 34, of Orem, Utah; Chief Warrant Officer Jonah D. McClellan, 26; Staff Sgt. Joshua D. Powell, 25, of Pleasant Plains, Ill.; and Sgt. Marvin R. Calhoun Jr., 23, of Elkhart, Ind. The military said McClellan was from Minnesota; his father said his son grew up near Battle Ground, Wash.
The cause of the crash was not immediately clear. NATO said there were no reports of enemy fire at the time in the Daychopan district of Zabul province, where the crash took place.
However, the Taliban have claimed that insurgents shot down the helicopter. The Taliban often exaggerate their claims and sometimes take credit for accidents.