Ottawa-based Swing N Scaff Inc. pleaded guilty to the charge in a Toronto court, and also faces a 25 per cent victim fine surcharge.
One of its directors, Patrick Deschamps, pleaded guilty to failing to ensure the platform was in good condition and that it was designed by a professional engineer. He was fined $50,000.
Four migrant workers plunged to their deaths when the swing stage meant to hold two people collapsed.
They were among six people doing repairs on a high-rise building's balconies.
Alesandrs Bondarevs, Aleksey Blumberg, Vladamir Korostin and Fayzullo Fazilov fell 13 floors to their deaths. The men ranged in age from 25 to 40 years old and were from Latvia, Uzbekistan and Ukraine.
The construction company, Metron Construction Corp., pleaded guilty two years ago to criminal negligence causing death and was eventually fined $750,000 plus a victim surcharge — the first time in Ontario that the Criminal Code has been used to hold a company responsible for a worker's death.
Another director, Joel Swartz, was ordered to pay $90,000 plus a $22,500 victim surcharge fine for four convictions under the Occupational Health and Safety Act.
A spokesman for the Ministry of Labour says criminal and occupational safety charges against a supervisor are still outstanding.