"We are calling on the leadership of the house to bring common sense gun control legislation to the House floor," Georgia Representative John Lewis said after asking his colleagues to join him on the floor. "Give us a vote. Let us vote. We came here to do our job. We came here to work."

Connecticut Senator Chris Murphy, who led last week's filibuster on gun control, has joined them in solidarity.

More from CNN:

While the House was recessed, dozens of House Democrats joined the sit-in in the well of the House reading names of gun victims to visitors in the House galleries.

Ohio Rep. Joyce Beatty, who exited the chamber briefly, told CNN that Democrats planned to stay "as long as we need to — all day, all night."

South Carolina Rep. Jim Clyburn, a veteran of the civil rights movement like Lewis, told CNN he didn't know how long Democrats planned to keep the sit-in going.

Other lawmakers joining Lewis include Florida Rep. Frederica Wilson, Michigan Rep. Dale Kildee, Louisiana Rep. Cedric Richmond, Connecticut Rep. Jim Himes and Conneticut Rep. John Larson.

UPDATE: At least two of Washington's Democratic reps are there:

UPDATE: Washington Senator Patty Murray is on her way too.

C-SPAN hasn't been live streaming the event because House Republicans turned off the cameras, declaring the House no longer in session. Follow House members' tweets here. Here's a live Periscope feed.