Washington Post pieced together timeline video after rioters got in, and graphics of how close they came:
Edit: I have watched it twice now:
This is
VERY good Timeline for inside the building. It really gives an understanding of how the pieces you saw before fit.
How two critical actions saved lawmakers. We have seen them before.
Officer Goodman leading them away from an open door where Mike Pence is with his Family. If that Mob went in that direction. It would have been a disaster. Bravery and
incredibly smart thinking on his part. This time it's showing with overhead tracking diagram.
Later Mob was trying to break through to the House Gallery (Floor was evactuated) where many house members are still sheltering. Plains clothes officer was guarding a choke point. He couldn't let any of the mob through that chokepoint. Ashley Babbit was shot as the first one trying to breach. House members heard the shot, and they can be heard saying removing your pins. Fearing the Mob was breaking through and didn't want to make it easy to identify them. After Babbit was shot, the rest of the House Member were evacuated.
Then it was mostly a fight to push rioters out of the building.