O'FALLON, Mo. — Teachers in at least three states have died after bouts with the coronavirus since the dawn of the new school year. A teachers’ union leader worries that the return to in-person classes will have a deadly impact across the U.S. if proper precautions aren’t taken.

AshLee DeMarinis was just 34 when she died Sunday. She taught social skills and special education in Potosi, Missouri.

A third- grade teacher died Monday in South Carolina. And two other educators died recently in Mississippi. It’s unclear how many teachers in the U.S. have become ill with the coronavirus since the new school year began.