Today marks the anniversary of the 'Battle of Hogwarts,' and J.K. is apologizing for another 'Potter' death

May 2 may seem like an ordinary day to some; but to Potterheads, it's the mark of the sad, but triumphant Battle of Hogwarts.

SEE ALSO: 8 insanely cool (and secret) facts about the Wizarding World of Harry Potter in LA

The gruesome events that took place in "Harry Potter and the Deathly Hallows," ended the Second Wizarding War, and quite a few lives as well. Author J.K. Rowling takes to Twitter every year to divulge the one character that she apologizes for killing (last year it was Fred Weasley). This time, it was Remus Lupin.

Rowling took to Twitter to express to all "Harry Potter" fans her guilt. "Once again, it's the anniversary of the Battle of Hogwarts so, as promised, I shall [apologize] for a death. This year: Remus Lupin," Rowling wrote on Twitter.

As we all know (well, all Potterheads know), Professor Remus Lupin was introduced in the third book, "Harry Potter and the Prisoner of Azkaban," as the new Defense Against the Dark Arts teacher. Lupin was a friend of Harry's parents, and he and his wife Nymphadora Tonks play a huge role in "Harry Potter and the Order of the Phoenix."

Check out her full explanation in her Twitter apology below.

Long live Lupin.

Check out more Potter love in the gallery below.

More on AOL Entertainment:
Gigi Hadid stuns in sexy mini-dress while celebrating 21st birthday (again!) in Las Vegas
EXCLUSIVE: George Lopez 'assisted' Prince's family following the late singer's death
Chrissy Teigen shares precious photo of daughter Luna's bath time