How a series of mistakes led to the siege of the Capitol

With the police in charge and guns drawn, the group stumbled through the mess, Mr. Crow said. Some police rushed to barricade other doors to block the mob. Others pinned some rioters to the ground so the legislature could pass.

In an effort to limit the number of people in the chamber, several lawmakers and aides took shelter in their offices scattered across the complex. Some were not contacted by the police even though they barricaded themselves inside.

Many of the members of the house stayed in a safe place where they might have been exposed to someone with the coronavirus, the attending doctor’s office said on Sunday.

Representative Lisa Blunt Rochester, Democrat of Delaware, urged a handful of Republicans to wear masks in vain. Representatives Hakeem Jeffries, Democrat of New York, and Liz Cheney, Republican of Wyoming, kept the room updated with updates as lawmakers called their families and checked their staff.

On the Senate side of the Capitol, the rioters got dangerously close to lawmakers. As they got closer, a quick-thinking Capitol policeman pushed one of them, then backed away and the crowd followed him. The officer’s maneuver helped lead the mob away from an entrance to the Senate several feet away a video recorded by Igor Bobic, a HuffPost reporter.

In a safe, unknown location, Republican Senator Lindsey Graham yelled at Senate Sergeant Michael C. Stenger, asking for a plan, and ordering him to evacuate the rioters, someone in the room said. Mr. Stenger was on his way, said the person and did not inspire confidence that he had the situation under control. He has since resigned, as has Chief Sund. Urgent voices crackled on police radios throughout the Capitol, giving details of the siege.

“There was definitely a heightened sense of urgency” in police radio as rioters broke through the east side of the Capitol, said Ashan M. Benedict, the head of the Washington Office’s Alcohol, Tobacco, Firearms and Explosives branch who worked with the Capitol Police nearby Republican Party Headquarters where a pipe bomb was found.