US President Donald Trump's tweet on Friday confirming that he and his wife had tested positive for coronavirus shocked the world.
With Mr Trump now in hospital, there are growing questions about how the pair were exposed to the virus.
A crowded Rose Garden event is coming under intense focus - the ceremony on 26 September where Mr Trump formally announced his nomination of the conservative Amy Coney Barrett for the Supreme Court. The World Health Organization says it commonly takes around five to six days for symptoms to start after contracting the virus.
Footage from the scene showed few attendees wearing masks. The seating was not set two metres (six feet) apart, while some bumped fists, shook hands or even hugged one another in greeting.
Eight people who attended are now confirmed to have the virus - although it is unclear exactly where and when they caught it. Aside from the president and the First Lady:
- New Jersey ex-Governor Chris Christie announced he had the virus on Saturday
- Kellyanne Conway, who resigned as Mr Trump's senior adviser in August, confirmed on Friday she had tested positive
- Mike Lee, a Republican senator from Utah, confirmed his positive test on Twitter, as did North Carolina senator Thom Tillis
- The University of Notre Dame confirmed their president, Reverend John Jenkins, also has Covid-19
- An unnamed journalist who attended the event also has the virus, according to the White House Correspondents' Association
Mr and Mrs Trump tested positive after the president's communications director, Hope Hicks, contracted the virus. She did not attend the Rose Garden event.
Guidelines published by the Centers for Disease Control recommend six feet of distance between people outside your home, and covering your nose and mouth when others are around you.
Dozens of lawmakers, family members and staff from the White House were at the event. Those who have tested positive were seated in the first few rows of the crowd.
Gatherings of more than 50 people at an event are banned under Washington DC coronavirus regulations, although federal property like the White House is exempt.
The Washington Post reports that authorities have left contact tracing efforts to the Trump administration. An official from Mayor Muriel Bowser's office told the paper that if all eight people were infected at the event, it would be one of the highest community spread incidents Washington DC has experienced.
City council member Brooke Pinto told the Washington Post it was "disappointing that the White House has flaunted not wearing masks and gathering large crowds".
"That is not only dangerous messaging for the country, but it is directly threatening to our efforts to decrease our spread across the district," she said.
Some of the event last Saturday also took place inside.
The president stood next to Amy Coney Barrett as she delivered her speech. Ms Barrett tested negative on Friday, according to a White House spokesperson.
Vice-President Mike Pence and his wife Karen also tested negative. Mr Pence sat across the aisle from Mrs Trump at the ceremony.
Attorney General William Barr sat in the same row as the vice-president. A Department of Justice spokesperson announced on Friday that Mr Barr had tested negative.
Johns Hopkins University coronavirus trackers say that 7.3 million people in the US have contracted the virus, the highest figure in the world.
The country also has the highest death toll, with more than 209,000 people killed.