Rioters had broken through the thin police line on the Capitol steps and were descending on hundreds of lawmakers conducting the ceremonial, quadrennial act of certifying the presidential vote — and the mayor and her aides were not able to stop the attack.
Ms. Bowser and her police chief called the Pentagon, asking for additional D.C. National Guard troops to be mobilized to support what officials were realizing was inadequate protection at the Capitol. But they were told that the request would first have to come from the Capitol Police.
In a call to Chief Steven Sund of the Capitol Police, they learned that his force was under siege, lawmakers were being rushed to safety, and rioters were overrunning anyone in authority. He kept repeating the same phrase: “The situation is dire.”
…Capitol Police and the city’s Metropolitan Police had rebuffed offers days before for more help from the National Guard beyond a relatively modest contingent to provide traffic control, so no additional troops had been placed on standby. It took hours for them to arrive.
…Federal agencies and the Capitol Police appeared to issue no serious warnings in the days leading up to the riots that the gathering could turn violent, despite countless posts on right-wing social media sites pledging confrontation and even bloodshed.
…Once the Capitol building was breached, a patchwork group of reinforcements was forced to try to navigate a labyrinthine complex of unfamiliar passages and byways that would prove dangerous.
…Hundreds of rioters carrying long guns and Molotov cocktails breached the seat of American power — some with the clear intent of injuring, holding hostage or even killing federal officials to stop them from certifying the vote.
…Law enforcement and other officials were aware of the chatter and took some steps to try to reduce the chances of violence. Homeland security officials put tactical agents on standby in downtown Washington. The F.B.I. questioned neo-Nazis who were under investigation and planning to attend the demonstrations.
…Chase Jennings, a spokesman for the Homeland Security Department, said in the days leading up the breach at the Capitol, the agency “had open channels with partners and shared information on those channels.”
…The Justice Department was treating the event as relatively peaceful, officials said. The acting attorney general, Jeffrey A. Rosen, worked on Wednesday from his office rather than the F.B.I. war room, where the crisis response unfolded.
…“The evidence is starkly clear that the momentum of violence has shifted to the right in this country. We’ve seen this in city after city,” Mr. Eddy said. “There was a failure among law enforcement to imagine that people who ‘look like me’ would do this.”
…Lawmakers had no clear evacuation plan and were forced to improvise.
Mr. Crow said he moved other lawmakers away from the barricaded door inside the gallery, helped them don hoods to protect against tear gas, had them remove their House lapel pins to avoid being targeted and took out his only possible weapon: a pen.
After nearly 30 minutes, he said, the Capitol Police and unidentified SWAT team officers cleared a path outside the gallery, above the House floor, and hustled out the lawmakers.
With the police in the lead, guns drawn, the group stumbled through the mayhem, Mr. Crow said. Some police officers rushed to barricade other doors to block the mob. Others pinned some rioters to the ground to allow the lawmakers to pass.
Because of efforts to restrict the number of people in the chamber, several lawmakers and aides were sheltering in their offices, scattered across the complex. Some were not contacted by the police, even as they barricaded themselves inside.
…On the Senate side of the Capitol, the rioters came perilously close to lawmakers. As they approached, a quick-thinking Capitol Police officer pushed one of them, then backed away, and the crowd chased him. The officer’s maneuver helped lead the mob away from an entrance to the Senate several feet away.
When the rioters breached the Capitol, Senator Kevin Cramer, Republican of North Dakota, said a quick prayer.
As he and the other senators made their way out of the chamber to the basement, an officer urged them to hurry because the rioters were on their heels.
“‘Move quicker, people,’ the officer said. ‘They’re right behind.’ It was serious,” Mr. Cramer recalled.
Out of immediate danger, senators took roll call. Four were missing, including Senator Tammy Duckworth, Democrat of Illinois, who uses a wheelchair after sustaining injuries in Iraq. She had barricaded herself in her office.
…Mr. Benedict [of ATF] connected with a commander of the Capitol Police SWAT team who was inside the complex, who acknowledged that they needed immediate help but said he needed a moment to arrange the official request.
A.T.F. and F.B.I. teams were soon headed to the Capitol. Neither bureau trains its agents for crowd control or riots, and they would have to find a way in, where they could help clear the Capitol and rescue staff members and employees.
When Mr. Benedict and his deputy finally got into the building, it was madness, he recalled. Clouds of noxious gas — bear spray, he guessed, from rioters — floated through the halls. With the help of a Capitol Police officer, they helped usher their teams through a growing crowd of rioters on the building’s south side.
…Thirty-three miles away, in Annapolis, Md., Gov. Larry Hogan, a Republican, was on a video conference call with the Japanese ambassador when his chief of staff rushed into his office, telling him, “The Capitol is under attack.”
The governor’s phone rang minutes later: a call from Representative Steny H. Hoyer of Maryland, the House majority leader.
…He says, ‘Governor, I’m in a room with Nancy Pelosi and Chuck Schumer. We need help. What can you do?’”
By then, the mob had breached the security outside the building, and Ms. Bowser and her staff members had begun making urgent calls to mobilize larger numbers of D.C. National Guard troops and move those already in the city to the Capitol. In the days before, Ms. Bowser had requested only a relatively small contingent of 340 D.C. National Guard troops, and only to control traffic and help protect public transportation stops, an effort to avoid the militarized federal presence that had been a major factor in the protest response in June.
One of the calls was to Mr. Hogan, asking the governor to dispatch Maryland National Guard troops to the city.
…Mr. Hogan’s phone rang. It was Ryan D. McCarthy, the secretary of the Army and the de facto head of the D.C. National Guard. He asked whether Maryland troops could come immediately.
“I said, ‘Yes, we’ve been waiting,’” Mr. Hogan recalled.
Ms. Bowser was having similar problems. Even during the phone call when Chief Sund said he needed National Guard troops to beat back the rioters — a request the mayor and her staff members figured would immediately prompt an order of reinforcements — Pentagon officials would not commit to sending them.
…“We are not denying the request,” the general insisted. But, he added, he would have to seek approval first. The phone call ended.
Inside the mayor’s command center, where officials recalled the debacle in June when the military sent a helicopter to Black Lives Matter protests, frustration turned to anger.
…Inside the besieged Capitol, lawmakers were making their own urgent requests to the Pentagon. Representative Elissa Slotkin, Democrat of Michigan and a former defense official, called Gen. Mark A. Milley, the chairman of the Joint Chiefs of Staff, to plead for help from the National Guard.
…Ed Roessler, the police chief in Fairfax County, Va., was driving when his phone rang at 2:27 p.m. A deputy told him that a request for help had just gone out over the police mutual aid radio system used by law enforcement agencies in the Washington region. He was stunned.
…About 40 Fairfax County officers were quickly deputized by an official from the United States marshals and sent to Washington. At the Capitol, they assembled in a wedge formation and went inside, where they helped push out rioters.
Then they stood guard while officers from other agencies built a larger security perimeter around the Capitol.
…Other requests for help went out, and the Capitol Police also sought assistance from the Homeland Security Department, but not until more than an hour after the rioters had surrounded the Capitol and the police had first fired what appeared to be flash-bang grenades.
When the request came at 2:30 p.m., the Secret Service deployed both uniformed and special agents, according to Kenneth T. Cuccinelli II, the acting deputy secretary of homeland security, the parent agency of the Secret Service.
……Finally, at about 3 p.m., Mr. Miller decided that all available D.C. National Guard soldiers — 1,100 troops — would be deployed.
…“Josh Hawley started the whole thing, and all who assisted him, they’ve got to be held accountable,” Mr. Manchin said.