HOUSTON -

Arson investigators Thursday morning were called out to a northwest Houston apartment complex after five cars were destroyed in a fire.

The flames were put out quickly but it destroyed the five vehicles. Fire officials tell us the fire was intentionally set, but they don't know if it was intended to destroy the vehicles.

"A ball of fire, just a ball of fire," said Cynthia Rodriguez.

Residents were shocked by the scene outside their homes Thursday morning. Charred metal and melted plastic was all that remained of five vehicles after the fire.

"We heard the explosions, I don't know if it was the tires or what but the vehicles were exploding," Rodriguez said.

At around 4:15am, Houston firefighters responded to an apartment fire at Johanna near Amelia. When firefighters arrived, they found multiple cars on fire in the apartment complex parking lot.

Three SUVs, a pickup truck, and a car all destroyed.

All five vehicles were parked next to each other underneath a carport. Residents saw the flames and called for help.

"They just knocked on my door to let me know that my cars were on fire," says Rodriguez.

Ruben Sifuentes, whose expedition was destroyed, says this isn't the first time this has happened at the apartment complex. He says last year multiple cars were burned in the same spot.

Arson investigators were on the scene all morning collecting evidence trying to figure out what caused this fire.

"There is no saving my truck. When I came outside my apartment there was a lot of fire. I lost my truck," said Ruben Sifuentes.

Fire officials are still determining how and under what circumstances this fire was set.