An under-supply of bus drivers caused a Maine elementary school to close its doors to students on Monday, according to our news partner WMTW. Kermit Elementary School in Swanville was closed.

WMTW reports that many Maine school districts have been dealing with this problem for years. The average salary for bus drivers in Maine is $19,950, according to Salary.com. To be a school bus driver in the Pine State, a person must be at least 21 years of age and have held a driver's license for at least one year, as per the Maine Legislature. Click here for the other requirements.