On Today’s Episode:

• Arson Disrupts Trains Ahead of Opening Ceremony at Olympics, by Aurelien Breeden, John Yoon and Andrew Das

• Harris Narrows Gap Against Trump, Times/Siena Poll Finds, by Shane Goldmacher, Ruth Igielnik and Camille Baker

• Obama Endorses Harris for the Democratic Nomination, by Jazmine Ulloa and Reid J. Epstein

• Speculation Swirls About What Hit Trump. An Analysis Suggests It Was a Bullet, by Malachy Browne, Devon Lum, and Alexander Cardia

• Two Top Mexican Cartel Leaders Are Arrested by U.S. Authorities, by Alan Feuer and Natalie Kitroeff

• Scenes From the Front Lines as Wildfires Rage in Canada and the West, by The New York Times

Tune in, and tell us what you think at theheadlines@nytimes.com. For corrections, email nytnews@nytimes.com.

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