Did you even read the page you linked?

> Brian David Sicknick (July 30, 1978 – January 7, 2021) was an American officer of the United States Capitol Police who died of an unknown cause a day after the 2021 storming of the Capitol.

> The day after the storming, anonymous Capitol police officers told The New York Times that Sicknick sustained his injuries by being struck by a fire extinguisher while physically engaging with protesters. However, no corroborating evidence of this has been discovered, and medical examiners found no signs of blunt force trauma. The New York Times published a correction retracting the previous claim, noting that investigators have found little evidence that he was struck by a fire extinguisher.