“I am going to what he did,” (sic) the now-deleted comment read. It was posted under a Discovery UK documentary about the 1966 Texas University shooting, in which a former marine shot dead 18 and injured over 30 others from atop the main building tower at the University of Texas at Austin.

The chilling comment came nine months before 19-year-old Nikolas Cruz went on a shooting rampage in and around Marjory Stoneman Douglas High School in Parkland, Florida. He killed 17 people and injured over a dozen with his AR-15 and possibly other weapons.

READ MORE: Mass shooting in Florida school leaves 17 dead

Other students at the school, cited by various US media outlets, said Cruz had kept a stockpile of guns, and suggested the attack was carefully planned. Cruz reportedly triggered school fire alarms intentionally to get students and teachers to exit classrooms, maximizing the casualties.

READ MORE: Florida school shooter identified as 19yo former student

It is not immediately clear whether the Nikolaz Cruz YouTube account, with nine subscribers and no publicly visible video uploads, belonged to the shooter, but it was suspended for “violent content” hours after the Florida shooting, apparently following the discovery of the comment.