Back wheels of a Toledo fire truck became stuck in a sinkhole during a medical run.
Objects were reportedly set ablaze in an alley, and two fires were reported at fast food dumpsters.
Video on Thursday afternoon had 39,000 views and more than 1,300 shares on Facebook.
Swearing-in ceremony was held in City Council Chambers.
It is unknown what the substance was nor how the officers were exposed to it.