22 MARCH: LONDON, ENGLAND – Prime Minister Theresa May makes a statement outside Downing Street following the terrorist incident in Westminster.

(Photo credit: Richard Pohle – WPA Pool/Getty Images) 

Incidents like this are extremely rare, which is why they make the news. If you feel worried, speak to an adult you trust.

Keep an eye on First News Today – our news bulletin made with Sky News – for updates.