An entire infantry battalion - dead - in a couple of minutes.
Christmas Eve, six months after D-Day.
The Battle of the Bulge had just started, one week earlier.
Probably troop replacements.
The USA and Britain completely controlled the surface of the English Channel.
That must have been an incredible shock.
I am skeptical about the 50 year secret.
Dozens of senior grade officers would have known about this.
If you read the article carefully the soldiers were only told to remain silent during the War.
Then American documents were declassified in 1959.
It was only British documents that were classified until 1996.
In wartime it is standard practice (of all participants of almost all wars) to minimize bad news to keep civilian and military morale as high as possible.
That is one reason why wartime reporting cannot be trusted (again no matter what side) during the war.