A truck driver who was performing a truck-to-truck fuel transfer when the Sunrise Propane explosion happened says he was trained in the illegal procedure by the company.

Felipe De Leon told a Toronto courtroom Thursday about the training, as well as the moments that preceded the deadly explosion, before fellow employee Parminder Saini was killed.

After the first small explosion, De Leon said he and Saini had different reactions.

"Then he ran towards where the sound was," De Leon said of Saini. "Because I was startled, I ran towards the fence."

Then came bigger, secondary explosions, which killed Saini.

Lawyers for Sunrise intend to argue that the company was allowed to transfer propane between trucks.

“[De Leon] had checked the vehicle, he was doing everything appropriately when he saw the smoke,” Sunrise lawyer Leo Adler told CBC News outside the court.

Sunrise faces several charges under provincial labour and environmental laws for its role in the Aug. 10, 2008, explosion at the 62 Murray Rd. fuel depot, in the Keele Street and Wilson Avenue area. The early-morning blast killed one employee, levelled several buildings and forced the evacuation of thousands from the Downsview neighbourhood.

An Ontario Fire Marshal’s report into the explosion found that an illegal tank-to-tank transfer was underway at the time of the explosion and that a propane leak resulted from a hose failure. The ignition source of the blast has not been identified.

The report noted that tank-to-tank and truck-to-truck transfers are both dangerous and illegal in Ontario. Sunrise had been warned about the practice prior to the explosion.