Following the pro-Trump rally in Washington D.C. Wednesday, the U.S. Capitol building was stormed, leaving four people dead, The Associated Press has confirmed.

D.C. Police Chief Robert Contee said Ashli Babbitt, an Air Force veteran, was shot by the U.S. Capitol police, as well as three others – two men and one woman – who died in “medical emergencies.”

Babbitt was part of a crowd that was breaking down the doors to a barricaded room where armed officers stood on the other side, police said. She was shot in the chest by police and was taken to a hospital where she was pronounced dead.

52 people were arrested and 14 police officers were injured during the demonstrations, according to Contee.

The FBI started an investigation, asking for the public’s help in identifying unlawful individuals. The agency’s Washington field office launched an online form for “information related to violent activity at the U.S Capitol Building.”

D.C. Mayor Muriel Bowser announced a 15-day extension of the public emergency she called for earlier in the day to “ensure peace and security through the inauguration of President Joe Biden and Vice President Kamala Harris.”

She added, “Today may be a dark day for our democracy, but there is hope and change coming.”