Authorities are investigating a deadly shooting at a Walmart store in Thornton, Colorado. At least three people, two adult males and one adult female are confirmed dead, according to police. Authorities say they do not have a suspect in custody. Just before 6:30 pm local time, Thornton police tweeted that a shooting had occurred at the Walmart on Grant Street saying "multiple parties" were down. Thornton, a suburb of Denver, is approximately 10 northeast of the city.