Cop Brian D. Sicknick may have been ‘killed by chemical agent’ after he was hit by fire extinguisher in Capitol protests

A US Capitol cop who was hit in the head with a fire extinguisher during clashes in DC may have been killed by a "chemical agent", say new reports.

Officer Brian D. Sicknick - today hailed a hero by his family - was fatally hurt in a clash with MAGA rioters on Wednesday and returned to his division office where he later collapsed.

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The officer was then taken to a nearby hospital where he was placed on life support, according to Capitol Police union chairman Gus Papathanasiou.

He died of his injures around 9:30pm on Thursday, the US Capitol Police said early on Friday.

A rioter assaulted the officer with the extinguisher, one source told NewsNation on Thursday.

Papathanasiou told WUSA9 that Sicknick suffered a stroke during the riots while the New York Times reported that he was also hit by the fire extinguisher.

Another official told the Times a "chemical agent" may have led to his injuries. 

“It was not clear if the blunt force had killed him; a chemical agent may have led to his death,” NYT reported, citing a source.

US Capitol Police said: "The death of Officer Sicknick will be investigated by the Metropolitan Police Department’s Homicide Branch, the USCP, and our federal partners.

"Officer Sicknick joined the USCP in July 2008, and most recently served in the Department’s First Responder’s Unit.

"The entire USCP Department expresses its deepest sympathies to Officer Sicknick’s family and friends on their loss, and mourns the loss of a friend and colleague."

His brother told ABC7: "After a day of fighting for his life, he passed away a hero.

"I would like to thank all of his brothers and sisters in law enforcement for the incredible compassion and support they have shown my family. "

Sicknick, who was in his 40s, had been with USCP since 2008 - most recently serving in the first responder unit.   

More than 50 Capitol Police and Metropolitan Police Department officers were injured, according to authorities, as a result of protests aimed at preventing Congress from certifying President-elect Joe Biden's win.

Four Trump fanatics who have died have been identified as Ashli Babbitt, 35, who was shot dead in the Capitol building; while Roseanne Boyland, 34, Kevin Greeson, 55, and Benjamin Phillips, 50, died after suffering "medical emergencies."

Trump supporters pushed through barriers around the perimeter of the Capitol around 1pm ET on Wednesday, and skirmishes ensued with officers in riot gear.

Some MAGA fans called the officers "traitors" for standing their posts.

About an hour-and-a-half later, the protesters had entered the Capitol building, according to police.

Police and protesters engaged in an armed standoff at the entrance of the House chamber around 3pm, with cops drawing their guns at an individual who was trying to break through.

US Capitol Police Chief Steven Sund is resigning after lawmakers including House Speaker Nancy Pelosi expressed frustration over the force's lack of preparedness given President Donald Trump had been promoting a rally to block Biden's victory.

Sund's resignation is effective Jan. 16, four days before Biden's inauguration, a Capitol Police official said.

In a statement on Thursday morning, Sund said that Capitol and other law enforcement officers were "actively attacked" with weapons including metal pipes.

"They were determined to enter into the Capitol Building by causing great damage," Sund stated.

Capitol Police responded to reports of pipe bombs and a suspicious vehicle on the southeast corner of the Capitol and officers "determined that both devices were, in fact, hazardous and could cause great harm to public safety," Sund said.

Babbitt, an Air Force veteran, was shot in the chest by a Capitol Police officer after she climbed into the building through a window.

The officer who fired the shot has been placed on administrative leave as Capitol Police and the Metropolitan Police Department conduct a joint investigation.

Boyland's family in Georgia said she was trampled in the Rotunda, after police said she might have been crushed in the mob.

Greeson, who had high blood pressure, had a heart attack and fell to the sidewalk.

Phillips, a computer programmer who started the website Trumparoo for President Donald Trump's fans to talk, died of a stroke.