ET caught up with Danny DeVito on the set of It's Always Sunny in Philadelphia just two days after the Orlando massacre, where the actor's thoughts were still with the victims and their families.
"I don't even want to talk about anything else," DeVito told ET's Ashley Crossan. "I love doing the show and thank you very much for being interested, but it's heartbreaking. I can't get over it."
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On June 12, 49 people were killed and more than 50 were injured at Pulse nightclub by a gunman wielding a Sig Sauer MCX rifle -- a weapon originally designed for U.S. Special Operations forces.
"It's a gun that we shouldn't have in our country," DeVito said. "It's one thing to have a hunting rifle or a target pistol, but this gun is just made to butcher people. It's an awful, awful thing, and we just let it go. You and I and everybody out there, we have to figure out a way to stop them."
The Golden Globe winner is a longtime advocate of gun control organizations and was an attendee at last month's premiere for the documentary Under the Gun. The film, executive produced by Katie Couric, explores America's history of gun violence and examines why action to curb gun violence has failed despite mass shootings.
Coincidentally, multiple gun violence reform measures were presented to the Senate on Monday -- one that would have intensified the background check system and another that would have barred gun sales to anyone who has been on a terrorist watch list in the last five years. None of them were passed by the Senate.
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"Nobody in the government is reliable to get rid of these guns," DeVito said. "The only people who can get rid of the guns are people. We can go march in the streets and say, 'This can't be.' We can't let this continue."
Watch the video below to see Beyonce pay tribute to the Orlando victims' families during an emotional concert in Detroit last week.