Aaaah ... the good old days ... 1.2 million men lost, just counting the Brits mind you, in slightly more than four months during the battle of the Somme. Almost a third of those lost in the first couple of weeks. Entire units wiped out, some showing 75% casualties, slow walking in lines into concentrated artillery and machine gun fire. Madness. Utter madness.
Correction: that figure was 1.2 million for all sides and nationalities in a little over four months. That's what I get for working from memory. Still, a huge waste.