A workplace death in Tecumseh is being investigated by OPP and the Ministry of Labour.
Ministry of Labour spokesperson William Lin says a worker from Pannunzio Mechanical died while working on a job at New-Tec Tool Ltd.
The Harrow man went to the top the building to fix the air conditioning unit at 5345 Brendan Ln in Oldcastle.
The company truck was still onsite Wednesday morning when employees from the tool company returned.
They discovered the mechanical worker on the roof with no vital signs, says Lin.
OPP are on also on scene.