DETROIT – Local health departments across Michigan started sounding the alarm months ago.

A deadlier coronavirus variant that had first ravaged Britain was now here — in metro Detroit, at the University of Michigan, a state prison in Ionia and rural counties in the Thumb region — with doctors, nurses and public health officials fully aware.

And yet Michiganders — from state prison employees to small business owners and local officials to parents of high school athletes — ignored medical experts' repeated warnings about the highly infectious variant. They rebuffed stay-in-place recommendations, allowed crowded events to occur and turned a blind eye to defiant behavior, according to thousands of internal health department emails and contact tracing notes from across the state and interviews with those in charge.

All the while, schools and restaurants reopened and mask and quarantine rules were relaxed. Overwhelmed health departments struggled to talk to oftentimes-angry infected patients, battled with school superintendents and parents who wanted a return to youth sports and fought losing battles to institute lockdowns or change state policy.

Michigan became the worst COVID-19 hot spot in the nation, and is among the worst states for the British variant. As of mid-April, it was at a record-high for childhood hospitalizations — an alarming virus situation that the Detroit Free Press, part of the USA TODAY Network, sought to explain by collaborating with Columbia University journalists and researchers who zoned in on the U.K. variant when it first turned up in the state.

Researchers found that the B.1.1.7 variant quickly ran rampant in Michigan, triggering COVID-19 clusters and variant outbreaks at the University of Michigan, multiple high schools, a prison, an insurance company, a day care, a dairy farm, a nursing home and a Grand Rapids hospital.

And that was only the beginning.

The British variant's warpath in Michigan is documented in internal emails and memos obtained through the state’s Freedom of Information Act, along with interviews with state health officials, the Michigan Department of Corrections and local health departments in several counties.

The documents and interviews show how the U.K. variant, which is approximately 60% more transmissible and 67% more deadly than the original coronavirus strain, spread quickly across Michigan. ...