"fireworks set off" is correct and usable in written English.
It can be used when referring to the act of igniting fireworks for entertainment and celebration. Example: The night sky was filled with colors as fireworks were set off for the Fourth of July.
Yesterday's fireworks, set off at two sites, were detonated electronically by uniformed pyrotechnicians from a large fireworks company.
In 1858, the cupola was ravaged by a blaze started by fireworks set off during the celebration of the completion of the trans-Atlantic cable.
The work refers to a fire started by fireworks set off by a provincial government official, which resulted in the death of a firefighter.
Another was creating visual embroidery for a stage work that drew its power from the emotional fireworks set off in that dreary drug chamber.
The birds don't seem to have been poisoned; one theory is that they were traumatized by fireworks set off for New Year's.
According to testimony at the trial, the departing guests angrily complained that loud fireworks set off by the Gavina children had frightened their younger children.
In February a cameraman covering a protest in Rio de Janeiro died after being struck by a firework set off by two of the group's members.
In February a television cameraman covering a protest in Rio de Janeiro died after being struck by a firework set off by two "Black Blocs", members of an anarchist group.
Someone ignited a flare or a firework, setting off the stampede, said Deputy Mayor Miguel Ángel Villanueva.
Rubio was in her house with her three children when she suddenly started hearing the faint, shrill sound of a firework setting off — a whistle, a pop and a crack to which she was accustomed in Tultepec.
Later in the evening, skyrockets and other fireworks were set off on the front campus.
