The F.B.I. said it was investigating the bomb threats, which disrupted life on more than a dozen campuses, as racially or ethnically motivated violent extremism and hate crimes.
After an unrelenting spike in cases, a small but growing list of districts including Newark, Atlanta, Milwaukee and Cleveland moved temporarily to remote learning.
After an unrelenting spike in cases, a small but growing list of districts including Newark, Atlanta, Milwaukee and Cleveland moved temporarily to remote learning.
Live Updates: Omicron Upends Return to School in U.S. nytimes.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from nytimes.com Daily Mail and Mail on Sunday newspapers.