Four people died, including one woman who was shot by a police officer, amid protests and rioting on Capitol Hill by supporters of Donald Trump who swarmed inside the building amid a session of Congress to certify Joe Biden's election win, triggering unprecedented chaos and violence at the heart of American democracy and accusations the outgoing president was attempting a coup.
In a late-night news conference, Metropolitan Police Department Chief Robert J Contee said that 52 were arrested over the violence that saw pro-Trump rioters breaking windows, climbing on rafters, ripping down U.S. flags and roaming the Senate chamber. Lawmakers were told to grab gas masks as police deployed tear gas inside the Rotunda, the ornate area under the dome that connects the House and the Senate, according to the Washington Post.
Both the House and Senate and the entire Capitol were placed under a lockdown. Vice President Mike Pence and lawmakers were evacuated to safe locations.
Security forces fired tear gas in a four-hour operation to clear the Capitol.
Vowing not to be deterred, Congress resumed their work on certifying Biden's Electoral College win, with debate stretching into the early hours of Thursday. After debate, the House and Senate rejected two objections to the tally and certified the final Electoral College vote with Biden receiving 306 votes and Trump 232 votes.
The chaos at the Capitol came a day after Biden enjoyed a new triumph, with his Democrats projected to win two Senate seats in runoffs in Georgia -- handing the party full control of Congress and dramatically increasing Biden's ability to pass legislation, starting with new Covid-19 relief.
Historians said it was the first time that the Capitol had been taken over since 1814 when the British burned it during the War of 1812.
Trump has only two weeks left in office but, with little on his public schedule for weeks and multiple reports he is losing his grip on reality, several news reports said his cabinet was whispering about removing him as unfit for office under the 25th Amendment to the Constitution.
"President Trump's willingness to incite violence and social unrest to overturn the election results by force clearly meet this standard," all Democrats on the House Judiciary Committee wrote in a letter to Vice President Mike Pence.
In an angry, rambling speech outside the White House before the violence, Trump urged his supporters to march to the Capitol and demanded that Pence, who ceremonially led the session, intervene to reverse their loss.
But Pence -- dutifully loyal to Trump for four years and quiet since the election -- said in a last-minute statement that he did not believe he had authority to intervene.
Thousands of Trump supporters headed to Washington at his urging in recent days, with downtown businesses boarding up in fear of violence and Mayor Muriel Bowser ordering a curfew Wednesday night.
"I can't say I respect our election process anymore," said Gail Shaw, 76, who drove down from New Jersey. "We will take our nation back."
Biden won in excess of seven million votes more than Trump in the November 3 election and leads him 306-232 in the state-by-state Electoral College count that determines elections, with Republicans unable to prove in court a single allegation of fraud.