Shots were fired Monday afternoon at the U.S. Capitol Visitor Center in Washington, D.C.

According to the Capitol's sergeant-at-arms the "shooter has been caught," and "One police office shot, but not seriously." EMS units reportedly responded to calls to treat multiple injuries at the building.

Capitol workers were told by authorities to shelter in place due to a "potential security threat." House staffers received an email shortly before 3:00 p.m. ET saying that no one can exit or enter any Capitol buildings and if you are outside to seek cover immediately.

Shootings at the Capitol are not entirely new: Three years ago, 34-year-old dental hygienist Miriam Carey attempted to drive through a White House security checkpoint in her black Infiniti G37 coupe, striking a U.S. Secret Service officer in the process. She was chased by authorities to the U.S. Capitol, where she was fatally shot. In 1998, two Capitol Hill police officers—Jacob Chestnut and John Gibson—were killed by a gunman, Russell Eugene Weston Jr., who reportedly suffered from paranoid schizophrenia.

Back in 1835, then-President Andrew Jackson survived an assasination attempt after leaving the U.S. Capitol. The individual, Richard Lawrence was not able to fire a shot because his guns did not discharge. More than one-hundred years later, four Puerto Rican nationalists shot semi-automatic pistols from a balcony inside the House of Representatives; five representatives were injured at the time.