Taking a stand. Conan O'Brien spoke out during his opening monologue on Monday, June 13, about the Orlando nightclub shooting and called for tougher gun control laws when it comes to assault rifles, which he called "weapons of war."

"At a time when we think we've heard the worst stories about senseless violence in our country, that it couldn't possibly get worse, the news out of Orlando yesterday is still impossible to fathom," he told viewers of the shooting, which left 49 dead and 53 injured, at Pulse, a gay club. "That so many people can lose their lives so quickly because of one person's demented rage will never make sense and God help us if it does."

The gunman, Omar Mateen, who was shot dead by police, had walked into the Florida club in the early hours of Sunday, June 12, with an AR-15 semiautomatic rifle — the same high-velocity weapon used in the mass shootings in San Bernardino, California, last December; and in Newtown, Connecticut, and Aurora, Colorado, in 2012.

"I am not a pundit, I am not an expert and I've always, always made it a policy to stick to my job and keep my opinions to myself. I have really tried very hard over the years not to bore you with what I think," O'Brien, 53, said.

"However, I am the father of two, I like to believe I have a shred of common sense and I simply do not understand why anybody in this country is allowed to purchase and own a semiautomatic assault rifle," he told the audience, who applauded in response. "These are weapons of war and they have no place in civilian life."

"I have tried to understand this issue from every side and it all comes down to this: Nobody I know or have ever met in my entire life should have access to a weapon that can kill so many people so quickly," he continued. "These mass shootings are happening so often now that lamenting them afterwards is becoming a national ritual."

"I do not know the answer," the host acknowledged. "But I wanted to take just a moment here tonight to agree with the rapidly growing sentiment in America that it's time to grow up and figure this out."

Several celebrities and public figures have spoken out in favor of tougher gun laws in the wake of the incident and on Monday, presumptive Democratic presidential nominee Hillary Clinton called for stricter laws and a ban on assault weapons.

"It's essential we stop terrorists from getting the tools they need to carry out their attacks," the former secretary of state said during a rally in Cleveland. "And that is especially true when it comes to assault weapons like the ones used in Orlando and San Bernardino. Weapons of war have no place on our streets."

Jimmy Fallon also spoke about Orlando in his opening monologue on Monday's Tonight Show, telling viewers he didn't know what to tell his two young daughters about the "senseless shooting."

"Maybe there's a lesson from all this. A lesson in tolerance," he said. "We need to support each other's differences and worry less about our own opinions. Get back to debate and away from believing or supporting the idea that if someone doesn't live the way you want them to live, you just buy a gun and kill them. Bomb them up. That is not OK."

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