On May 17, 2000, a Notice of Violation for a Severity Level III was issued. The action was based on the failure to control and maintain constant surveillance of licensed materials. Specifically, a portable nuclear density gauge containing 10 millicuries of cesium-137 and 50 millicuries of americium-241 was left unattended for a short period of time. During that time the gauge was run over by a construction vehicle and was crushed.