The discovery of a "mold-like" substance in the high school gym resulted in Tuesday's classes canceled for all students in Blissfield Community Schools in Lenawee County, Michigan. 

There will also be no technology classes Tuesday, the district said in announcements posted on the high school's social media. 

"It was brought to our attention that a mold-like substance was found on some hard surfaces in an isolated area in the high school gymnasium," the letter issued to parents Monday evening said.  

Cleaning and testing is taking place Tuesday. 

"Without the high school students in attendance, we will fall below the state requirement of 75% District attendance to count as a school day. As a result, we will be cancelling classes for elementary school and middle school tomorrow as well. Sorry for the inconvenience, we will work diligently to resolve the issue." 

Monday was the first day of school in the district, to include the Senior Sunrise ceremony at the soccer field. 

Blissfield is the third Southeast Michigan school district whose back-to-school schedules were disrupted for cleanup and remediation of suspected mold. Dundee Community Schools in Monroe County and Saline Schools in Washtenaw County also have been dealing with that situation. 

The above video originally aired on Aug. 25.