Fred's death.
While Fred was dueling with the Death Eater he threw a nasty spell to the Death Eater's side. A smile played across his lips. The smile left as soon as it had come.
The Death Eater grinned and showed Fred the side of his cloak. In small, untidy letters matched to Fred's handwriting spelled out 'Spell-proof cloaks'
Fred looked sad and raised his wand to throw another spell out, but the Death Eater had sensed what was coming.
The Death Eater yelled out the one Unforgivable Curse that would ensure the victim wouldn't be able to recover. The Killing Curse.
A green light shot out from the Death Eater's wand, straight at Fred's chest.
Fred Weasley fell to the floor with a sickening thump.
His eyes remained open until his family came looking for him.
Molly Weasley cried uncontrollably into Arthur Weasley, while Percy stared down at him, tears leaking down his face.
George was the worst. He sat next to his twin, sobbing. After everyone had found out Fred died, the grief-stricken family left to go to the Hospital Wing. All except George, who refused to leave his twin's side. When George was alone with Fred he bent down to his face and whispered in his ear, "I don't like this prank, Fred. Please, wake up."