I was chasing the rabbit down the Wikipedia hole today (I started looking at NFL injuries, go figure) and came across the number in http://en.m.wikipedia.org/wiki/French_invasion_of_Russia.
That number is staggering to me and, having only found it today, seems it would be as big a reason as the cold and hunger for Napoleon to have left Russia.
Did the Russians get deep in to the French lines and kill commanders or something? Has this number of general officers being killed ever been topped since then?
They were killed during the Battle of Borodino. This was one of the fiercest battles of the Napoleonic wars and the bloodiest single day battle of the era. The Russians were well protected by "fleches" or field fortifications and the center of their line was anchored by a large earthen fort that became known as the Great Redoubt. Marshal Davout wanted to turn the Russian's left flank, but Napoleon rejected that plan. The Russian army had slipped away to many times, between June 22 and September 7. Napoleon did not want that to happen again, so he ordered a frontal assault against the Russians at the place their general, Kutusov decided to make his stand.
Source: "Fighting techniques of the Napoleonic age" edited by Robert Bruce, Iain Dickie, Kevin Kiley, Michael Pavkovic and Fred Schneid. 2008