To some, the reasons for the disparity are obvious: The University of Alabama flagship campus in Tuscaloosa has 37,842 students, making it larger, and younger, than Birmingham, which has 22,500 students. The Tuscaloosa campus also has ranked as the nation’s No. 1 party school, according to the Princeton Review, with a feverish devotion to the Crimson Tide football team and a large Greek system so powerful that it is nicknamed “the Machine.” About 1 in 4 Tuscaloosa students live in dormitories or Greek houses, compared with 1 in 10 at UAB.

“Alabama has a very large party culture,” Zachary Johnson, 19, a sophomore majoring in news media at the campus in Tuscaloosa, said in late summer as cases surged. “Many people want to go out and party.”

University officials tried to curb those impulses by moving the Greek rush recruitment program online, and both schools barred outside visitors from entering dorms. But there are other key differences: Tuscaloosa did not switch to take-out-only dining halls until after classes began, while Birmingham started that at the outset. Nearly half of Birmingham’s students are attending class online this semester, while most of Tuscaloosa’s opted to return to campus for a mix of in-person and virtual courses.

Tuscaloosa Mayor Walt Maddox (D) said coronavirus clusters popped up in fraternities and dorms. And crowds swelled on “the Strip,” a dimly lit area of town packed with bars, late-night eateries and golf-cart taxi system called “Joyride.”