A growing number of lawmakers are testing positive for COVID-19 after being forced to crowd together in a secure space during Wednesday’s mob attack on the Capitol, confirming fears that the insurrection created conditions for a virus superspreader event.

At least three House members have tested positive in the past 24 hours: Democratic Reps. Bonnie Watson Coleman (N.J.), Pramila Jayapal (Wash.) and Brad Schneider (Ill.). All were in the secure space where security officials ushered hundreds of lawmakers to shelter in place as rioters in support of President Trump rampaged the Capitol.

Lawmakers are revealing their diagnoses voluntarily; it’s not yet clear who else in the room had COVID-19 or has since tested positive after being exposed.

Democrats are furious that several House Republicans in the room were not wearing masks, in violation of rules in place since July requiring masks on the House floor and in surrounding office buildings.

A video obtained by Punchbowl News showed six House Republicans not wearing masks in the crowded room and declining blue surgical masks offered by Rep. Lisa Blunt Rochester (D-Del.).

One of the maskless Republicans, Rep. Markwayne Mullin (Okla.), can be heard saying, “I'm not trying to get political here.”

Reps. Marjorie Greene (R-Ga.) and Andy Biggs (R-Ariz.) can also be seen smirking and averting their eyes as Blunt Rochester tried to convince them to put masks on. GOP Reps. Doug LaMalfa (Calif.), Michael Cloud (Texas) and Scott Perry (Pa.) were also not wearing masks.

Democrats will now start enforcing the existing mask rules starting Tuesday night by adopting additional rules to impose fines on members who don’t wear masks on the House floor.

Lawmakers will be fined $500 for the first offense and $2,500 for the second, to be deducted from their pay, according to a senior Democratic aide.

Earlier Tuesday, Democratic Reps. Debbie Dingell (Mich.) and Anthony Brown (Md.) introduced a bill Tuesday that would impose a $1,000 fine — per day — on any lawmaker who doesn’t wear a mask on the Capitol grounds.

“We’re done playing games. Either have some common sense and wear a damn mask or pay a fine. It’s not that complicated,” Dingell said in a statement.

Watson Coleman, Jayapal and Schneider each received the first dose of the Pfizer-BioNTech COVID-19 that’s being distributed to members of Congress. Pfizer has said the vaccine is only about 52 percent effective after the first dose, and becomes 95 percent effective after the second dose is administered three weeks later.

Watson Coleman, a 75-year-old cancer survivor, said Monday that she had mild, “cold-like symptoms” but was en route to a local hospital for monoclonal antibody treatment at the advice of her doctor.

The rules established by Speaker Nancy Pelosi (D-Calif.) starting in late July prohibit any lawmaker from entering the House chamber or even being recognized to speak if they are not wearing a mask. But those rules have not always been strictly enforced.

“This is not a joke. Our lives and our livelihoods are at risk, and anyone who refuses to wear a mask should be fully held accountable for endangering our lives because of their selfish idiocy,” Jayapal said in a statement.

Schneider similarly endorsed sanctions against lawmakers without masks. He stressed that he doesn’t know for sure that he got COVID-19 while sheltering in place in the crowded secure location, but said it was the most risky situation he’s been in during the pandemic.

“Let me be clear, I don't know from whom I got this virus or even necessarily got it in that room. But I know that my exposure in that room was greater than at any other time through this entire pandemic, of anything else I've ever been to,” Schneider told reporters. “The fact that three of us have so far tested positive I think reinforces that.”

Other lawmakers forced to stay in the crowded room on Wednesday expressed concern that they may have been exposed.

“It was gross. It was completely unsafe,” Rep. Mondaire Jones (D-N.Y.) said of his GOP colleagues without masks in the room where they were all evacuated from the House chamber. “And they kept escorting members of Congress to the room.”

“So eventually I became more concerned that I would get COVID-19 from my Republican colleagues than would die at the hands of the insurrectionists,” Jones said.

The Capitol physician, Brian Monahan, informed lawmakers on Sunday that people in the secure space during Wednesday's mob attack "may have been exposed to another occupant with coronavirus infection."

Five people, including a Capitol Police officer and a rioter attempting to break into the House chamber, died during Wednesday’s mob attack on the Capitol. The rioters, egged on by Trump at a rally earlier in the day, were trying to stop Congress from ratifying President-elect Joe Biden’s Electoral College victory.

More than 50 Capitol Police and Metropolitan Police officers were also injured, including several who had to be hospitalized.

Lawmakers ultimately certified the election results around 3:45 a.m. Thursday after the Capitol had been cleared of the mob.

The possibility of a superspreader event from Wednesday's attack on the Capitol isn't limited to members of Congress.

Most of the rioters were not wearing masks as they rampaged the Capitol — likely raising the risk of spreading COVID-19 among themselves and to the police officers with whom they came into close contact. People in the mob flew to Washington at Trump's behest from all over the country and those who were not arrested at the Capitol may have exposed others during their travels.

Several other House members have tested positive for COVID-19 in the past week since the new session of Congress began on Jan. 3, including GOP Reps. Kay Granger (Texas), Kevin Brady (Texas), Gus Bilirakis (Fla.), Jake LaTurner (Kan.), Michelle Steel (Calif.) and Chuck Fleischmann (Tenn.).

All voted on the House floor in the days before learning they had tested positive.

Since March, at least 49 House members and seven senators have tested positive for COVID-19, while several others have tested positive for antibodies or had presumed cases. And in late December, Rep.-elect Luke Letlow (R-La.) died from COVID-19 days before he was set to be sworn in on Jan. 3.

Updated: 5:37 p.m.