On this day in conspiracies

The Stanley Hotel opens as an upper-class resort, among the first fully electrified hotels in the country, powered by a hydroplant Stanley built that also brought electricity to the town of Estes Park.

In the Kielce pogrom, a mob including police and soldiers murders more than forty Holocaust survivors after a blood-libel rumor. As the U.S. Holocaust Memorial Museum documents, the violence fed on the belief that Jews had imposed communism on Poland; it convinces many surviving Polish Jews they have no future there and spurs mass emigration.

Under pressure to cut roughly 100,000 rail jobs, Shimoyama's administration releases a first dismissal list of about 30,000 employees. The rail unions, among the most powerful in occupied Japan, react with fury, and Shimoyama is reported to have received threats.

Mattress Firm is founded in Houston, Texas. Over the following decades it grows from a regional specialty retailer into the largest mattress chain in the United States, mostly by buying competitors.

The ATLAS and CMS collaborations announce the discovery of a new particle consistent with the Higgs boson, at a mass near 125 GeV, to a packed auditorium at CERN. It confirms a decades-old prediction about how particles acquire mass; Peter Higgs and François Englert share the 2013 Nobel Prize in Physics.

The IAEA publishes its comprehensive safety review, concluding that Japan's discharge plan is consistent with international safety standards and that the release as designed would have a negligible radiological impact on people and the environment.

In the pre-dawn hours, slow-moving storms unload many inches of rain over the Guadalupe River watershed. The river rises about 26 feet in roughly 45 minutes near Kerrville, sweeping away homes, vehicles, and a riverside girls' summer camp. More than a hundred people are killed, most of them in Kerr County. It becomes one of the deadliest inland flash floods in modern Texas history.

The event: roughly 400 people associated with Patriot Front march through central Washington, near Union Station, the Capitol, and Metro stations, during the America 250 celebrations. They wear matching clothes, masks, and sunglasses and carry American and Confederate flags with anti-immigrant messaging. NBC Washington, WUSA9, Newsweek, The Advocate, and Religion News Service, among others, report it as it happens. No injuries are reported.