Trevor “McSkillet” Heitmann, a popular Counter Strike: Global Offensive player and YouTube creator, is dead following a multi-car collision that occurred just outside of San Diego on Thursday afternoon.

A spokesperson for the San Diego County Department of Public Safety confirmed the driver involved in the crash was Heitmann. Two people on Twitter claiming to be close friends of Heitmann tweeted about his death prior to the official statement.

“This isn’t a hoax,” one friend, who goes by shnaxler, tweeted. “He was my best friend in real life and I’ve been dealing with this pain for the past two hours. Everyone please spread love and support, he was battling an incredible rough time and we need to show support. RIP to @OG_McSkillet. You truly were my best friend and biggest inspiration in life. I know you were dealing with an incredibly hard time but I know heaven will treat you well. I love you so much. Thank you for all the amazing times.”

“Hasn’t been [confirmed] anywhere but he’s dead,” said another friend, who goes by exqu1ty. “He was my friend since we both live in SoCal and we met through a mutual who knew him growing up. Will not release details of his death, but he is dead.”

Another friend, who asked to remain anonymous, told Polygon that Heitmann began pushing people away a few months ago, adding that their friends were mourning his death.

“I don’t know how to feel,” they said. “I knew him so well in middle and high school, he was a really good person and we had a lot of great memories together, but now learning about all the tragedy he caused for the people who died, I don’t know what to feel.”

Heitmann’s friends said he was dealing with depression ahead of the crash.

The crash killed Heitmann, two others and left another in serious condition, according to the Los Angeles Times. A representative for the California Highway Patrol told Polygon the other two victims in the crash were a mother and daughter. The crash was reported around 4:45 p.m. PT, and eyewitnesses told police it was caused by Heitmann’s car speeding down the highway in the opposite lane. The car was driving at more than 100 mph at the time of the crash, according to the Times.

Heitmann was best known for owning a popular CS:GO trading site, CSGO Magic, and for participating in CS:GO’s skin trading community. He was known as the “king of skins” to other CS:GO YouTube creators. Many of his videos focused on skin trading. In June, Heitmann received a trade ban from Valve, meaning he could no longer trade any of the items and weapons he kept in his inventory. Some YouTube creators, and CS:GO skin traders, like Sparkles, suggested that Heitmann’s inability to trade could have cost him $100,000.

Heitmann made a sizable profit through skin trading. He published a video in December 2017 showing off his 2014 Mercedes-Benz McLaren 650S, and acknowledged that most of his earnings came from CS:GO.

CS:GO Magic, the site Heitmann co-operated, was shut down in 2016 after Valve updated its policies about skin gambling sites leveraging Steam as a way to attract players.

Heitmann’s presence on YouTube had dwindled over the past year. The last video he uploaded was five months ago.

Update: Officials confirmed it was a mother and daughter who were killed. We’ve updated the story with that confirmation.