The teen who took home $3 million after winning the Fortnite World Cup last month was swatted while streaming the video game from his home.
"Did he just leave mid-game?" another gamer could be heard asking.
Off-camera, Giersdorf was heard speaking with his father, saying, "I've been swatted."
"Swatting" is a harassment tactic, in which someone reports an emergency at a perceived enemy's or rival's home in order to get police and SWAT teams to respond to the location.
When Giersdorf eventually returned to the stream, he explained what had happened.
"Yeah, I got swatted ... Dude, they came in with guns, bro. They literally pulled up," Giersdorf said. "The internet is f------ crazy."
Giersdorf said he was able to defuse the situation so quickly because one of the responding officers lived in his neighborhood and recognized him. Giersdorf told the other players he got lucky.
It was not immediately clear who called in the swatting on Giersdorf. NBC News has reached out to Giersdorf for comment on the incident.
In a Facebook post, the Upper Pottsgrove Township Police Department said officers were dispatched after a call was received about a possible shooting. The caller, pretending to be Giersdorf, claimed that he had killed his father and tied up his mother.
Police surrounded Giersdorf's home, and then called in, which is when Giersdorf's father answered and then came to the door. Cpl. Albert Werner of the Upper Pottsgrove Township Police Department told ESPN that he believed the initial call came from Europe.
Swatting has had lethal consequences in the past. Andrew Finch, 28, was killed in 2017 as police responded to a prank 911 call from California about a shooting and kidnapping at Finch's home in Wichita.
Authorities said Finch, who appeared to have no connection to the prank caller, was shot by a Wichita police officer.
Barriss agreed to serve 20 to 25 years in federal prison as part of a plea agreement, according to the U.S. Attorney's Office in the Central District of Los Angeles.
CORRECTION (Aug. 13, 2019, 11:03 a.m. ET) An earlier version of this article misstated the day of the swatting. It was Saturday, not Sunday.