Your brother, Harry Bailey, broke through the ice and was drowne...
[George has discovered his brother Harry's tombstone]
Clarence: [explaining] Your brother, Harry Bailey, broke through the ice and was drowned at the age of nine.
George Bailey: That's a lie! Harry Bailey went to war! He got the Congressional Medal of Honor! He saved the lives of every man on that transport!
Clarence: Every man on that transport died. Harry wasn't there to save them, because you weren't there to save Harry.