The night that ended far differently started out normal. It was Thursday at Mekelburg’s, a busy Brooklyn grocery with a cafe and bar in the back and picnic tables on the patio, with locals tucking into sandwiches and sipping craft beers.

Everything changed at 7 p.m., when someone noticed a news story online. Word spread through the place like a rotten odor. Customers scanned their phones, looked up and signaled for the check.

“By 8:15, we were completely empty,” said Alicia Guevara, who owns Mekelburg’s with her husband, Daniel Mekelburg.

Slowly, she pieced together what had happened.

HuffPost had just published a profile of a prolific Twitter firebrand from New York, a woman who frequently attacks Islam — one post warned that “500K Muslims will Invade Europe this Summer” — under the user name @AmyMek.