Gwinnett County fire hazmat crews also responded to the scene and cleaned up the spill, the police report said. Lawrenceville police spokesman Capt. Greg Vaughn said the investigation has been turned over to Georgia's Environmental Protection Division.
The bus kicked off a nationwide tour Tuesday with stops in Lawrenceville, Atlanta and Macon.
"Georgia has become increasingly competitive for Democrats this election cycle," a press release announcing the tour said, "and the Democratic Party is campaigning in Georgia to provide additional support for Hillary Clinton and to promote Democrats up and down the ballot."