Within the span of two years during the Second War World, a mother from St. John's lost four sons.

A large rock with a big black anchor and chain sits in O'Brien Park on Signal Hill Road, as a monument for Margaret O'Brien and her four children who died during the war.

Engraved in the plaque are the names and dates of death of all four men — Maurice, Michael, James and David — and the name of their mother, who was recognized as "Newfoundland's most bereaved mother for World War Two."

Gary Green Crow's Nest Officer's Club

Gary Green with the Crow's Nest Officer's Club in St. John's did some research to learn more about the O'Brien family from Signal Hill Road. (Jane Adey/CBC)

Maurice O'Brien was the first of the four brothers to die, when the convoy he was on — the HMS Forfar — sunk in December 1940.

For the next two years after that, three other O'Brien brothers would die.

Their father, Maurice O'Brien Sr., also died in 1942, leaving behind his wife and their surviving son, Denis. 

David O'Brien died while working aboard the HMS Frisky — a tug boat that worked in St. John's harbour — in October 1942.

Michael O'Brien went down on the S.S. Eastlea in March 1941.

"James [O'Brien] is a complete mystery," said Gary Green of the Crow's Nest Officer's Club. "I could find nothing on him anywhere."

The Broadcast Host Jane Adey enlisted Green's help to piece together the history of the family. 

Monument to the O'Brien family on Signal Hill Road

A monument sits on Signal Hill Road in honour of Margaret O'Brien — 'Newfoundland's most bereaved mother for World War Two' — and her four sons who died within a two year period. (Jane Adey/CBC)

Green said information on the family, whose sacrifice to the Second World War is memorialised in downtown St. John's, wasn't readily available.

He would like people with information on the O'Briens to come forward to document their history.

"We have talked to numerous veterans over the years who tell incredible stories — none of which appear in the history books," Green said.

"This is just an incredible story about sacrifice that a family gave, but [also] the sacrifice of this woman."

Mrs. O'Brien didn't die until 1963, and by Green's research, the woman was well into the mid-80s.

"She had lived a long, full life and for a number of years afterward carrying all of this with her."

O'Brien Park plaque

A plaque in honour of the O'Brien family, who once lived on the very spot where the monument sits today on Signal Hill Road, provides a snapshot of the great sacrifice some families made during the First and Second World War. (Jane Adey/CBC)