New UPDATE

 Shawn Hubler, Giulia McDonnell Nieto del Rio, Marie Fazio, and Elizabeth Dias contributed to this article.

23rd of March, 2021

2:35 p.m. ET update

Authorities say a gunman opened fire at a grocery store in Boulder, Colorado, on Monday, killing ten people. A Boulder police officer, a young grocery store employee, and a retiree filling Instacart orders were among them.