Officer Sicknick did not die from being hit by a fire extinguisher because that never happened <https://www.snopes.com/fact-check/brian-sicknick-fire-exting...>. He died of a stroke which the autopsy found no connection with the riot <https://www.washingtontimes.com/news/2021/apr/19/brian-sickn...>.

The one person who died violently was one of the rioters, an unarmed woman who was shot by Capitol Police. Four other rioters died of natural causes around the time of the riot.