The U.S. Secret Service briefly locked down the White House on Tuesday after an object was thrown over the North Lawn fence, prompting agents to move reporters and television crews inside the James S. Brady Press Briefing Room and close nearby streets. The security alert began at roughly 11:30 a.m. EDT, halting live shots known as "Pebble Beach" and interrupting an outdoor interview with Education Secretary Linda McMahon. Pennsylvania Avenue and Lafayette Park were also sealed off while officers examined the item. Press Secretary Karoline Leavitt later told journalists the object was a cellphone that a passerby, believed to be a tourist, had tossed over the 13-foot perimeter fence. Officers declared the device safe and issued an all-clear about 30 minutes later, allowing reporters to return to the lawn by 11:56 a.m. No injuries were reported and President Donald Trump’s departure for an afternoon event in Pittsburgh proceeded on schedule. The incident is the latest in a series of minor perimeter breaches that have triggered precautionary lockdowns at the executive mansion.