The blaze was reported at about 5:30 a.m. at a towing company and junkyard in the 1400 block of 45th Avenue, Battalion Chief Melinda Drayton said.
An employee of Pito's Towing, located at 1421 46th Ave., said there was a fire at the business this morning but declined to comment further.
The fire was controlled in about 25 minutes, a fire dispatcher said.
At least three junk cars and one operational vehicle were destroyed in the blaze, according to Drayton.
Although the cause is still under investigation, there was heavy illegal fireworks activity in the area Monday night, she said.
"We suspect smoldering fireworks might have contributed to it, but that's preliminary," she said.
One firefighter injured his back while responding to the blaze and was treated by a doctor this morning, Drayton said.
>>Check out video submitted via uReport of the fire.