The "Harry Potter" universe has seen many deaths over the fictional universe's seven-year span, which in the books ran from the years 1991 to 1998. But there was one death in particular that series author J. K. Rowling regrets and has even taken to social media to apologize for it.

On her Twitter page, Rowling wrote, "Today I would just like to say: I'm really sorry about Fred. *Bows head in acceptance of your reasonable ire*."

She even went on to answer other tweets, which included ".‪@Brieuc26Rankin I thought I might apologise for one death per anniversary. Fred was the worst for me, so I started with him."

For those unfamiliar with the series, Fred Weasley was one of the prankster twins who have on many occasions aligned themselves with Harry. They returned for the Battle of Hogwarts and, after defeating Pius Thicknesse, Fred is killed following an explosion that was caused by Augustus.

In an interview on the Today show with host Meredith Veira back in 2007, Rowling revealed some of the reason for killing of characters.

"I wanted to kill parents," she told Veira, noting that it sounded "terrible" to say. "I wanted there to be an echo of what happened to Harry just to show the absolute evil of what Voldemort's doing."

But she also said she became attached to Arthur Weasley and could not quite send him away.

"If there's one character I couldn't bear to part with, it's Arthur Weasley," Rowling said. The character she was referring to had survived a snakebite in "The Order of the Phoenix."

"I think part of the reason for that is there were very few good fathers in the book," Rowling told Veira. "In fact, you could make a very good case for Arthur Weasley being the only good father in the whole series."

But when asked why Fred over George, Rowling's answer was less than enlightening, although she did somewhat elaborate.

"I always knew it was going to be Fred, and I couldn't honestly tell you why," Rowling said. "Fred is normally the funnier but also the crueler of the two. So they might have thought that George would be the more vulnerable one and, therefore, the one to die."

In hindsight, though, she did say, "Either one of them would have been terrible to kill."

Rowling admitted, "It was awful killing Fred. I hated that."