A week after James Holmes, who killed 12 people and wounded 70 at a midnight showing of “The Dark Knight Rises” in Aurora, Colo., in 2012, was convicted of murder, gunshots ripped through a movie theater again. This time, a shooter opened fire at the Grand Theater 16 in Lafayette, La., during a screening of Amy Schumer and Judd Apatow’s romantic comedy “Trainwreck,” killing two people and wounding nine others before committing suicide. It may be that the killer chose “Trainwreck” for a reason in the same way that Holmes styled himself after the Batman villain the Joker. But whatever his reasoning, it’s worth pausing for a moment to consider our specific losses as another arena of public life begins to feel unsafe.

These mass shootings aren’t the first time that movie theaters have seemed like dangerous places. As William J. Mann wrote in “Tinseltown: Murder, Morphine and Madness at the Dawn of Hollywood,” a 1920 panic at the New Catherine theater in New York resulted in a stampede: Six children, many of them immigrants, were crushed to death. Ellen O’Grady, the city’s first policewoman and the official “in charge of the city’s public welfare laws as they related to motion picture theaters,” used the tragedy to advocate for an NYPD crackdown on theater owners, including plans to arrest anyone who admitted a child without the protective presence of an adult.

But if the New Catherine theater was a mass tragedy with no one in particular to blame, the attacks in Aurora and Lafayette are something far worse. As American Film Institute president and Chief Executive Bob Gazzale said in a statement, “Going to a summer movie is a celebration of the American creative spirit and one of our nation’s most beloved pastimes.” And that beloved pastime, while not necessarily a moral act, is a deeply vulnerable one.

When you go to a movie theater, you are deciding to sit for two hours in the dark with dozens, even hundreds of people, you don’t know. Unlike on a plane, or even in a live theater or concert performance, to name other captive experiences that put us in close proximity with strangers, there often aren’t paid staff in the theater with you, watching for disruptions or quietly managing other people’s behavior. Often, if you’re polite, and if you want to give yourself fully over to the experience unfolding on the screen, you’ve turned off your phone, putting another step between yourself and calling for help if it should suddenly prove necessary.

Once the lights go down and the previews (and pre-previews, sadly) come up, we’re giving ourselves over not just to the conditions of the movie theater, but to the story on screen. This is what makes film so powerful, and what in the past has made it seem so threatening to decency crusaders who decried the medium’s impact on children and immigrants. Whatever divides us before we take our plushly cushioned stadium seats or our places in community theater chairs worn thin by decades of showings, we’ve been drawn together by the same story. And that story will continue to unite us, at least for a little while, as we spill back into the bright heat of summer daylight, or the cool of the evening, and talk about what we’ve just seen.

This isn’t to say that the movies automatically produce some kind of mindless consensus: We bring our differences into the theater with us, and they inform the sometimes radically divergent things we take away from the same images projected on hundreds of similar screens. The movies, though, can help define the parameters of our conversations. We may not want the same results out of a fantasy of American power projection such as “The Avengers” franchise, the glimpse into a president’s inner life on his most difficult days we get in “Lincoln,” or a brutal journey into the realities of slavery and the precarious nature of black freedom in “12 Years a Slave.” But there’s something powerful in finding ourselves attracted to the same basic narratives and the same big, American ideas.

We don’t think of movie theaters as sacrosanct spaces, the way we assume that schools or churches — the sites of other recent horrific mass shootings — will be. But the act of attending a film requires a similar, perhaps even greater, trust that a group of complete strangers can come together in fleeting community; that we can briefly stop sizing one another up and simply surrender to an experience together, in safety and shared wonder.