A TikTok account that potentially belonged to the Wisconsin school shooter is now deleted on the heels of complaints about racist comments on the page … TMZ has learned.

The account possibly belonging to 15-year-old Natalie Rupnow was first highlighted by the Anti-Defamation League’s Center on Extremism — and when we checked it out, we found it only had 2 posts, both related to the movie “Fight Club” … but they were flooded with comments that were clearly left after the tragedy in Madison, WI.

We confirmed with the ADL the username its people observed was @targetedbloodsport — and according to them, the account featured the phrase, “Totally nice day,” similar to “Totally normal day” … which the ADL claims is used by racists or white supremacists.

It says it’s code for “TND” or “total N-word death.”

Shortly after TMZ reached out to TikTok asking for more information about the account — it was deleted … with no explanation.

One of the videos on the account featured the song “Where is My Mind?” by The Pixies, which plays at the end of “Fight Club” once Tyler Durden’s plan is carried out. The other video featured Edward Norton‘s character with the caption, “Total schizo honestly.”

Police have not revealed Rupnow’s motive for the mass shooting.

As TMZ previously reported, the shooter might have had a partner in plotting the Madison mass shooting.

20-year-old Carlsbad resident Alexander Paffendorf is accused of exchanging messages with her to coordinate his attack on a local government building … while she attacked the Abundant Life Christian School.

Cops are hoping Paffendorf’s alleged exchange with Rupnow will shed light on the teen’s motive for killing 2 people and injuring 6 others … before fatally shooting herself.