The Secret Service closed off the front lawn of the White House, including to the news media, due to an unspecified incident. Press were relocated inside to the White House briefing room while waiting for an informal press conference with Education Secretary Linda McMahon. The lockdown, initiated around 11:30 a.m., was lifted approximately 30 minutes later. White House officials are investigating the situation. A comparable incident occurred in 2020 when the Secret Service evacuated President Donald Trump during a press conference and subsequently shot a man who claimed to be armed.
Source: https://www.washingtonexaminer.com/news/3471572/secret-service-shuts-down-white-house-front-lawn/