Mercury was released to the floor of the Robert A. Young (RAY) Federal Building when a mercury sphygmomanometer (blood pressure cuff) was broken. Initially a simple cleanup was performed by the local fire department. The EPA, with assistance from the Missouri Department of Natural Resources (MDNR), was called in to perform mercury vapor monitoring of the air. Due to the presence of visible mercury on the floor near the original spill and the levels of mercury in the air near the spill, the EPA and MDNR performed a more extensive cleanup of the area guided by a mercury vapor analyzer.