Firefighters extinguished at least three cars in North Bergen overnight, and a person was seen running from the scene of one of the incidents.
One car was parked on First Avenue when it caught fire, while a second was parked next to a house on 76th Street.
A third car fire was also reported.
Authorities have not confirmed the incidents are related.
They are looking for the man last seen running on 76th Street.
What used to be a 2005 Toyota Siena belonged to Stacey Sneyers. "It's what I had since my daughter was born and now it's gone. She's heartbroken, the family car she grew up with. It's gone," said Sneyers.
Hers was the worst of the cars torched within blocks of each other near Bergenline Avenue.
On 76th Street, a Toyota Avalon's interior was completely burned away as the car was right next to a home, which had to be evacuated.
Police say there was also a failed fire attempt on a BMW, all of this within a 40 minute span.
"Clearly it's arson. It's unnatural to have 3 start out of the blue," said North Bergen Deputy Police Chief Gerard Sanzari.
Sneyers says her brother heard the car alarm go on and off beginning around 4:10 a.m.
"By 5:25, my alarm was blaring, he looked out the window and my car was up in flames. By that time it was too late, no one could do anything. I can't understand why someone would set a car in fire, no rhyme or reason," she said.
While Stacey asks why, police want to know who.
"Right now we have no suspects, we're trying to find who did it, looking at private and city video to see if there is something there," said Sanzari.