But in an email, Mr. Birch said it was a true accident. Still, he said, he would not be putting signs up urging visitors to be careful. “We trust people.” Mr. Birch said. “Crowns are fragile things. They are symbols of power. Perhaps it’s ironic and meaningful that they fell.”

Museum selfies have become a thing, and are even encouraged by some museums to draw younger visitors. There are entire blogs dedicated to museum selfies. Museum Hack, which gives quirky, unofficial tours of major museums around the country says on its website, “Museum selfies are an awesome way to engage audiences with your museum and collections.”

Lisa Krassner, chief member and visitor services officer for the Metropolitan Museum of Art, said, “Visitors are here to enjoy our collection and exhibitions and the entire experience, and we welcome individuals capturing and sharing that experience through photography — as long as it’s done in a way that doesn’t endanger the art or interfere with the experience of others.”

(Museum officials are not as embracing of the selfie stick, which some, including the Met, have banned.)

Our Los Angeles woman is hardly alone in the annals of the selfie-clumsy. At the “Yayoi Kusama: Infinity Mirrors” exhibition at the Hirshhorn Museum and Sculpture Garden in Washington, a huge hit featuring immersive mirrors, part of the museum closed for three days after a patron shattered a glowing LED pumpkin in February.