Severe weather disrupted the marquee celebration of America’s 250th birthday, threatening an anticipated rally and speech in Washington by President Donald Trump who has sought to stamp his mark on the anniversary.
As a line of storms rolled into the region last night, authorities ordered a crowd that had assembled on the National Mall to evacuate the exposed area and shelter nearby.
The US Secret Service said it was not letting any more people through security checkpoints.
Mr Trump is delivering a speech to those gathered, which will be followed by fireworks.
Visitors had waited hours to get into the event, contending with stepped-up security and temperatures that reached 39 degrees Celsius.
A passenger looks on as members of Patriot Front ride the Washington Metro
The record-breaking heatwave forced the cancellation of several parades and other events in the area.
“It’s just part of the deal I signed up for,” said Glen Solander, 60, a software engineer visiting from Sioux Falls, South Dakota, as he waited at a security checkpoint yesterday.
Other visitors included the white nationalist organisation Patriot Front.
The group posted on social media that it had arrived in the capital and hundreds of people wearing the group’s outfits traveled to the city on Metro trains serving the District of Columbia region.
Local police said they had not received any reports of violence.
Past US presidents have generally avoided in-person appearances at 4 July celebrations, but Mr Trump has blurred the line between official commemoration and campaign-style politics.
The Trump administration’s Freedom 250 group has largely sidelined a nonpartisan body set up in 2016 to handle the 250th anniversary and has fenced off much of the 2.4km National Mall for a Great American State Fair – featuring attractions such as a Ferris wheel alongside displays by conservative groups and defence contractors.
Freedom 250 says the fair aims to showcase the people and innovations that make the US “the greatest nation on Earth”.
Several Democratic-led states declined to send delegations and many performers scheduled to appear dropped out, citing concerns about partisanship.
Freedom 250 says the fair aims to showcase what makes the US ‘the greatest nation on Earth’
Mr Trump opened the event with a rally on 24 June.
Crowds were sparse at first but have swelled in recent days, forcing visitors to wait in entrance lines that stretched several blocks.
Gift shops and restaurants at the Smithsonian Institution museums near the event reported near-record sales on Friday, said Frank DiGiovine, a Smithsonian executive.
Other activities with Freedom 250 branding include a faith rally featuring mostly conservative Christian speakers and multiple sports events, including a card of mixed martial arts bouts on the White House grounds for Mr Trump’s 80th birthday on 14 June.
An Indy Car race in Washington is scheduled for August.
The Freedom 250 organisation also sponsored “Freedom Trucks” that critics say paint an overly religious version of American history and gloss over issues such as slavery and racial injustice.
A Reuters/Ipsos poll found that a majority of Americans, including three-quarters of Democrats and half of Republicans, think the events celebrating the country’s 250th anniversary have grown too political.
Mr Trump has sought to remake wide swaths of the capital city ahead of the 250th celebration, with mixed results.
Many fountains and statues have been renovated, but problems have beset a much-touted $15 million renovation of the Lincoln Memorial’s Reflecting Pool.
Security cameras and soldiers now stand watch over its peeling paint and algae-fouled waters.