Images from across much of the country illuminate snow-covered streets and preparations for worse still to come.

Federal authorities said the slain man, Alex Pretti, had approached agents with a gun. But videos show Mr. Pretti was holding his phone, not a weapon, when they pulled him to the ground.

President Trump said he would impose tariffs if Canada made “a deal with China,” though there is no sign that those countries are discussing a broad trade agreement.