Just a Sig Op said:
The Royal Newfoundland Regiment was slaughtered after going over the top at Beaumont Hamel.
Well, they weren't Royal until later in the war.
But that is about the gist of it.
To expand - 1 July 1916 was the first day of "the July drive" - what later became known as the Battle of the Somme. The battle lasted til November, but the first day set the record for most casualties in a single day. The British Army lost 20,000 killed and 40,000 wounded in the space of 24 hours. Kind of like the entire Canadian Armed Forces jumping off and getting shot in a single day.
The Newfoundland Regiment had it especially bad; the front line trenches were so choked with dead, they couldn't move up to the start line so they had to go over the top from behind their front line trenches. 800 men left their trenches, and within 15 minutes or so over 700 of them were hit. None made it beyond the friendly barbed wire.
Much of the first day of the Somme was like that, though there were some pretty remarkable successes that day, also. By the time the battle ended four months or so later, hundreds of thousands on both sides had been killed, maimed, crippled or otherwise scarred.
If you meet someone who says they're from Newfoundland, but can't tell you what Beaumont Hamel is - they're lying.
Some feel tiny Newfoundland never recovered. While they sent artillerymen over in World War Two, never again have they sent a formed unit of infantry out on operations.
They had also suffered at Gallipoli IIRC - Newfoundland wasn't part of Canada until 1949 so they served as part of the British Army in both world wars.