A report of multiple shots being fired came out before 6:30pm Mountain Time at the Walmart on Grant Street.
Police said multiple parties were down but have not offered more details.
Police did not release information about any victims and it is not clear if an assailant has been taken into custody.
Thornton Police Department said on Twitter: “Shooting just occurred at Walmart, 9900 Grant St, multiple parties down. Please stay away from the area.”
More to follow…