"Brian D. Sicknick passed away due to injuries sustained while on-duty," the U.S. Capitol Police said in a statement late Thursday. "He returned to his division office [?] and collapsed. He was taken to a local hospital where he succumbed to his injuries."
[...] More than 50 law enforcement officials were injured and several were hospitalized, USCP said earlier Thursday.

The growing number [?!] of deaths from the unprecedented attack on Capitol Hill comes as the enormous complex faces a reckoning over its security, including the operations of its roughly 1,800-member police force. On Thursday, Capitol Police Chief Steven Sund, Senate Sergeant-At-Arms Michael Stenger and House Sergeant-At-Arms Paul Irving all resigned.

Sicknick was initially in critical condition [!] when reports of his death surfaced. But USCP confirmed in a statement that he died Thursday at about 9:30 p.m. USCP, the Metropolitan Police Department's Homicide Branch and federal law enforcement will investigate Sicknick's death.
[...]
"This tragic loss should remind all of us of the bravery of the law enforcement officers who protected us, our colleagues, Congressional staff, the press corps [!], and other essential workers yesterday," [House reps DeLauro, Ryan] wrote. "To honor Officer Sicknick's memory, we must ensure that the mob [!] who attacked the ["]People's House["] and those who instigated them are held fully accountable."