WASHINGTON — Sen. Chris Murphy attempted to pass a gun control package Thursday morning, watched it get blocked by Republicans, and then gave a speech about the need to do something about the regular mass shootings in America. He didn’t know until he walked out that another mass shooting had just happened, this time at a high school in California.

“I found out as soon as I walked off the floor,” Murphy told BuzzFeed News.

Two students were killed and several others were injured when a 16-year-old went on a shooting spree at a school in Santa Clarita on Thursday morning.

Murphy had asked for the Senate to unanimously agree to pass universal background checks for firearms, as he’s done repeatedly for months. “The American public are not going to accept silence from the body week after week, month after month in the face of this epidemic carnage that is happening in this country,” he said.

But even after news of the shooting spread through the Senate — Sen. Richard Blumenthal found out via a note from a staffer while he was giving a speech about gun violence — Murphy said he doesn’t believe it will change anything.

“I wish this weren’t the case, but Republicans’ interest in working on guns is driven by casualties of 15 or more. It’s so awful that it works like this,” he said. “I don’t doubt that we’ll be back in a conversation about background checks, but it probably won’t happen until there’s another epic-scale shooting.”

Some Republicans have long opposed the bill, arguing that universal background checks violate Second Amendment rights. Sen. Cindy Hyde-Smith, the Republican who objected to Murphy trying to get a vote on the bill Thursday morning, argued that the legislation “should not be fast-tracked by the Senate.”

“Many questions about this legislation need to be answered before it’s forced upon law-abiding gun owners," Hyde-Smith said.

In September, House Democrats advanced three additional gun bills following mass shootings in El Paso, Texas, and Dayton, Ohio, which left a total of 31 people dead. There was also momentum toward a bipartisan gun control package negotiated with the White House.

But Murphy said he hadn’t heard from the Trump administration about background checks since September.

Lindsey Graham, chair of the Senate Judiciary Committee, said there is bipartisan support for one part of a gun control package — a grant program that encourages states to set up “red flag” programs that allow law enforcement officers to preemptively seize a person’s firearms if they are deemed to be a danger to themselves or others. But he said progress on background checks has stalled, and blamed, in part, the House impeachment inquiry.

“Impeachment has sucked all the oxygen out. But I hope we will revisit. I really do. I am ready to do something yesterday,” said Graham.

The House passed universal background checks in late February. The bill received bipartisan support with eight Republicans crossing the aisle to vote for the legislation. Since then, universal background checks have remained stalled in the Republican-led Senate at the behest of Majority Leader Mitch McConnell.

Attorney General Bill Barr blamed the House impeachment hearings for derailing the progress on gun control during an event in Tennessee on Wednesday. But Murphy refuted those claims Thursday morning.

“That’s not true,” Murphy said, addressing Barr’s comments on the Senate floor. “The impeachment proceedings right now are in the House of Representatives; the discussion on the future of the background checks bill was in the Senate.”