An American flag will be raised Thursday outside Philadelphia City Hall in memory of Seaman Patrick M. Corcoran, a native son lost at sea during the Vietnam War.

It is the flag stolen last summer from the Corcoran family's home at the Jersey Shore and returned several days later.

The huge flag was presented to the family nearly 50 years ago at his funeral. It is expected to fly for several days at City Hall.

"I'm a little nervous. I hope they have somebody watching it," Corcoran's brother Tom, 56, of Langhorne, said Wednesday.

Corcoran said the honor for his older brother "is both a joy and a little melancholy. It just brings back a lot of memories."

Corcoran will arrive for the flag-raising with a motorcycle escort from a veterans' group that will accompany him from Brian's Harley-Davidson in Langhorne to City Hall.

Council is also expected to present a resolution Thursday honoring Patrick Corcoran and the 73 other sailors who died aboard the USS Frank E. Evans during a collision with another ship in 1969.

The resolution was introduced by Councilmen David Oh and Curtis Jones Jr. and calls upon the Defense Department to allow their names to be placed on the Vietnam Veterans Memorial in Washington.

The Evans was supporting U.S. forces from off the coast of Vietnam when it sank while participating in training exercises with five other ships.

But the Defense Department's casualty list did not include the Evans' sailors because the shipwreck occurred outside the official combat zone.

The designation kept their names off the Vietnam Veterans Memorial. The Corcoran family and the Evans Association, a group of veterans and their relatives, have been fighting for years to change that.

"The Vietnam War's combat zone boundaries, which were ill-defined and changed from time to time, should not be applied to exclude the names of the lost sailors from the Memorial," the resolution reads.

Louise Esola, author of American Boys, a book about the Evans, agrees that the names should be added to the wall.

"They've put names on the Vietnam memorial with less evidence than this," Esola said Wednesday. The Evans was given a service medal citation the day before the tragedy, and "to get that medal you have to be doing something related to the war," she said.

The Evans collided with an Australian aircraft carrier June 3, 1969, in the South China Sea. The Navy destroyer was cut in half, its bow sinking within minutes.

Patrick Corcoran, 19, of the Torresdale section, asleep in his rack, died along with the 73 others; their bodies were never recovered. Only 37 sailors survived.

The oldest of three children, Patrick Corcoran graduated from Father Judge High School in 1968 and decided to enlist in the Navy, following in his father's footsteps, his brother said.

Only 9 years old when his brother was killed, Tom Corcoran remembers seeing his father sitting with a transistor radio with the antenna pointed out the window trying to learn more about Patrick's fate after news about the collision.

Tom went to school that day, and returned home to learn that his brother was among the dead. "I came home, and there was a bunch of cars in front of my house. I found out about it," he recalled.

An American flag was presented to his father, Tom Corcoran Sr., by the military at a Mass in Philadelphia for Patrick in June 1969. The elder Corcoran kept the flag until he died in 2006.

The flag was passed on to Tom and their older sister, Suzanne Meissler, with instructions from their father to fly it occasionally. Thus began a family tradition.

This year, the huge flag was hoisted for the July 4 holiday next door to the Corcoran family's summer home in North Wildwood. Hours later, the flag was stolen.

After a frantic public appeal and search by police, the flag was returned anonymously by a woman who dropped it off at the neighbor's home.

Since then, Corcoran has kept the flag neatly folded in sight on his bedroom dresser. "It's not moving too far from my vision."

Tom Corcoran said the flag's theft brought renewed attention to the efforts to get the names of the Evans' sailors on the Vietnam memorial. Patrick Corcoran's name was added to the Philadelphia memorial in 1988, a year after it was dedicated.

"There are 74 skeletons in the bottom of the South China Sea," he said. "The least our government can do is give those boys the honor and dignity they deserve."

mburney@phillynews.com

856-779-3814 @mlburney