AIR7 HD was over the scene Wednesday evening as crews began the process of destroying the unexploded fireworks, which sent thick plumes of smoke into the air.
Authorities say they had collected dozens of boxes full of undetonated fireworks while combing the neighborhood that was rocked by multiple blasts Tuesday.
The mayor of Ontario says he was nearby when those explosions went off.
"It was indescribable how it feels to have that much of an explosion happen that close. Windows were bursting and people were crying," said Mayor Paul Leon.
The coroner has removed two bodies from the scene but they still have not identified the victims. The mother of 38-year-old Alex Paez told ABC7 on Wednesday that he and his cousin, 20-year-old Cesar Paez, were the deceased victims.
Police say it could be several days before neighbors are let back into their homes as the bomb squad disposes of the unexploded ordnance.
About 50 residents were given hotel vouchers for Wednesday night until they were allowed to return to their homes.