Connecticut Sens. Richard Blumenthal and Chris Murphy have had enough with Congress’ refusal to address gun violence.

On Monday, America woke up to news of a gruesome mass shooting at a country music concert near Mandalay Bay Casino in Las Vegas. According to reports, this is the deadliest shooting massacre in modern U.S. history.

But we have been here many times before, and everyone knows how the story will play out. And Sen. Richard Blumenthal of Connecticut, who represents the families of the children murdered five years ago at Sandy Hook Elementary, is fed up.

In a searing statement, Blumenthal condemned his colleagues for their refusal to debate any attempt to keep guns out of the wrong hands:

Although many details of this mass shooting remain unclear, one thing is certain: yet again, we are watching in horror as another American community is torn apart by the terrible devastation wrought by a gunman. My heart breaks for Las Vegas: the victims, their families, their friends, and the entire community. It has been barely a year since what was previously the largest mass shooting in American history — the deadly attack at Pulse nightclub. In the interim, thousands more have been lost to the daily, ruthless toll of gun violence. Still, Congress refuses to act. I am more than frustrated, I am furious.

Blumenthal was shortly joined by his junior colleague, Sen. Chris Murphy.

“Nowhere but America do horrific large-scale mass shootings happen with this degree of regularity,” Murphy said in a statement. “Last night’s massacre may go down as the deadliest in our nation’s history, but already this year there have been more mass shootings than days in the year.”

Murphy continued, calling on his colleagues in Congress to finally do something. “This must stop. It is positively infuriating that my colleagues in Congress are so afraid of the gun industry that they pretend there aren’t public policy responses to this epidemic. There are, and the thoughts and prayers of politicians are cruelly hollow if they are paired with continued legislative indifference.”

On one hand, there is still a lot about this shooting we cannot assume. We do not yet know the shooter’s motive, the weapons that were used, how he came to acquire them, or what combination of laws or reforms could have prevented it.

On the other hand, study after study shows gun violence rates increase where laws are more permissive, so some simple regulations on guns would prevent a number of mass shootings in this country, as well as gun murders and suicides.

And although neither Blumenthal nor Murphy mentioned no one by name, all the Republican leaders who are offering condolences and prayers, from Trump on down, are responsible for stonewalling any serious policy debate. Many of those Republican lawmakers have voted against sensible regulations that are supported by a huge majority of the country, including gun owners.

In fact, Republicans in the House will soon be voting on bills to weaken gun control laws, from restrictions on silencers to armor-piercing bullets. They are also debating legislation to force states to recognize concealed carry permits from every other state. And while President Obama lifted the CDC’s longstanding ban on gun violence research, Republicans still refuse to actually fund any studies that might suggest how gun violence works or what new laws might be needed.

Every day that Republicans put off a conversation on keeping Americans safe puts more blood on their hands. For lawmakers like Blumenthal and Murphy, who owe action to their constituents, the time to fight is now.