All-clear given at Metro Courthouse after 'suspicious substance' prompts hazmat response FBI now investigating WTVF Hazmat crews have been called to the Historic Metro Courthouse due to a report of a "suspicious substance." and last updated 2021-03-17 12:46:43-04 NASHVILLE, Tenn. (WTVF) â Firefighters have given the all-clear after hazmat crews were called to the Historic Metro Courthouse due to a report of a "suspicious substance." The Nashville Fire Department confirmed the call came in Wednesday morning at 1 Public Square. The department said the substance was sent to the first floor of the courthouse. Nashville Fire officials said crews removed the envelope and did not identify any dangerous substance.