As Nagasaki marked the 70th anniversary of its atomic bombing Sunday, some Japanese Internet users lambasted Disney, one of the largest American cultural establishments, for its alleged insensitivity to public sentiment here.

The controversy erupted Sunday afternoon after an ill-timed tweet was sent by the official Walt Disney Japan account saying “A very merry unbirthday to you!” from a song in Disney’s animated movie “Alice in Wonderland.”

However, in Japanese, the phrase from the film reads “Nandemo nai hi Omedeto,” which literally translates as “congratulations for a no special day.”

The message was accompanied by a picture of Alice from the Disney film.

Some Twitter users saw the tweet as highly offensive, in light of the gravity the Aug. 9 date carries among Japanese, with comments such as “Today is not a no special day,” and “Why choose today for such a tweet?”

Others, meanwhile, said the message was simply related to the children’s tale, with no malice intended from the Disney side.

The tweet went viral over the next few hours, prompting Disney Japan to delete it and later post an apology.