This is still such a shock to us — and as we learn more about investigators' findings, it may be a shock to them, too.
BMX legend Dave Mirraapparently committed suicide on Thursday, and now authorities in Greenville, North Carolina where he made his home believe there may be a specific reason the extreme sports star took his life.
The city's mayor, Allen Thomas, noted in a press conference that while authorities are still gathering facts, he fears Mirra may have had chronic traumatic encephalopathy, or as it's better known, CTE.
If you've heard those initials before, it's likely because of football.
Scientists are finding many former NFL stars who have either abruptly committed suicide or had otherwise violent outbursts towards those around them suffered from the degenerative brain disease that comes from years of head trauma associated with contact sports.
Mayor Thomas even mentioned former football star Junior Seau specifically, the famous San Diego Chargers linebacker who took his own life in 2012 and was later found to have been suffering from the brain condition.
The thought, according to Thomas and officials in Greenville, is that Mirra may have suffered similar problems after repeated hits to the head during his long career in extreme sports.
The city's police chief, Mark Holtzman, noted that investigators have spoken to Mirra's friends, who have confirmed they were with the BMX legend literally minutes before his death and nothing seemed amiss.
Whatever the case, as investigators work to learn more, our thoughts continue to be with Mirra's friends, family, and loved ones.