BBC reporter Gary O’Donoghue, who was covering the shooting at a Donald Trump rally in Butler, published “shocking” comments from an aide.
Trump was removed from the stage on Saturday (July 13) following an assassination attempt.
The attacker, 20-year-old Thomas Matthew Crooks, was shot and killed. One participant was killed and two others were injured.
In a video clip that is going viral on X/Twitter, reporter O'Donoghue urged viewers to "be prepared" and shared the "shocking" comment he had heard.
"Now I'm going to say something that's going to be shocking, but I think it's important to know," he said during the broadcast.
In another clip, the senior North America correspondent covered the incident while lying on the ground, which shocked many viewers.
"This is not an ideal situation but it's the only refuge we have at the moment," he said in the clip.
"He's an excellent journalist, surely his production team should have covered him here instead of letting him lie on the ground while cars go by in the background and three people walk by calmly," one viewer wrote.
He wrote, “I need to thank all the United States Secret Service and law enforcement officials who replied quickly to the shooting in Butler, Pennsylvania.
"Most importantly, I would like to increase my condolences to the family of the man who died in the collision, as well as the own family of the alternative guy who changed into critically injured.