This story was reported in partnership with Type Investigations .

DETROIT It was here before we knew it was here.

It was on Maddelein Street on the morning of March 6, when the 9th Precinct on the east side hosted a Police & Pancakes breakfast. About 100 people showed up, pooling syrup on paper plates and small-talking with officers, including a 43-year-old community leader named Marlowe Stoudamire , broad-smiling and beloved, who would be dead in three weeks.

It was almost surely downtown that evening, at the sprawling convention center on the Detroit River where Sen. Bernie Sanders enticed thousands to rally ahead of Michigans presidential primary. And likely, too, at a high school on West Outer Drive on the eve of the primary, when 2,000 supporters of former Vice President Joe Biden showed up for another shoulder-to-shoulder rally, getting a shot of hand sanitizer on their palms as they passed through the door.

Biden won the March 10 primary, with historically high turnout. Three hours after the polls closed, Michigans governor stepped before the cameras, far more staid than shed been at the Biden rally the night before. The coronavirus was here, she said. The first two cases were confirmed, both in the Detroit area. In scarcely a weeks time, the number of sick people multiplied 40 times over. Three died: one from Detroit, two from nearby suburbs.

The coronavirus was here, in one of the nations poorest and blackest big cities, a place where the incidences of asthma, diabetes and high blood pressure are all more than 50% above the national average. Proud of its history as a mobility hub, Detroit is also one of North Americas busiest land border crossings and home to an international airport where 1,100 planes pass through every day, including direct flights to Seattle, New York City, Rome, Seoul, Shanghai and Beijing.