Toronto Fire has been on scene since the fire began March 18 with firefighters continuing to apply water on the hot spots that remain.
It took nearly four hours and 80 firefighters to get the blaze under control.
The way the transformers were constructed there were pieces of wood, covered in oil between sections of copper and metal within the transformers said a Toronto Fire spokesperson.
The transformers will continue to smoulder for a while but exactly how long we dont know.
Richview Transformer Station is one of the largest Hydro One stations in Toronto with eight transformers on its site. Two of them went up in flames just before 5 p.m. that day.
A cause has yet to be determined.