Former Buffalo Bills safety Aaron Williams had his career ended prematurely thanks to serious neck injuries in back-to-back seasons. On Wednesday, he officially announced his retirement with a heartfelt letter. "I want to start with an apology. To the city of Buffalo," he started his retirement announcement on The Players' Tribune.

The letter, which is simply titled "To Buffalo," sees Williams critiquing himself for not taking his career seriously in the beginning. "I came into this league with two things on my mind: money and fame," he wrote. "The way I saw it, I balled out at Texas, so it was a given that I was gonna ball out in the NFL, too. Easy money, right? So when I first came in, I didn’t work very hard. I didn’t watch film. I didn’t study. I pretty much made it through my first two seasons on straight athletic ability. Football wasn’t a priority. I was more concerned with what kind of car this guy was driving or what club that guy was posting up at."

The letter is astonishingly honest, detailing Williams' mistakes and regrets. He said the moment things changed for him came when he met one particular young Bills fan. "This kid must have been like five years old, swagged out in Bills gear from head to toe," he wrote in the letter. "And I'll never forget, this kid... he was telling me how he wanted to play in the NFL one day—that when he grew up, he wanted to be just like me."

"That was the moment when I started to look at myself—like really look at myself—for the first time since I had gotten to Buffalo," he continued. He also addressed what those fateful injuries felt like at the time and how they affected him when he was released by the Bills following the 2016 season. He mentioned three tryouts that he had in 2017 but said none of the teams he tried out for would clear him because of the injuries.

He wrapped up the letter by thanking Bills fans. "I was born in California and raised in Texas. But Buffalo will always be the place where I grew up—where I became a man," he wrote. "No matter what comes next or where the next chapter of my life takes me, we’ll always have that. And I wouldn’t have it any other way."

Read Williams' touching letter here.