People who work on a commercial street near Dallas Love Field believe a passing plane is responsible for the purple mess that damaged vehicles.

It happened on Andjon Drive near Harry Hines Boulevard, which is directly in the flight path to the Dallas airport.

Despite rain Friday, the purple coating was still clearly visible on two company vehicles behind one business and it was all over the pavement there, too.

Vehicles at a neighboring business and at one across the street had also been damaged when the mess was first discovered Thursday morning.

Melissa Gunn, who works at one of the businesses, said she scrubbed and scrubbed to get the material off her personal car. She said people on the street were speculating about the cause.

“They're like, ‘We don't know what happened.’ They were saying, it just came from the sky. They thought it was a plane that dropped something out of it,” she said.

Across the street, Mary Beth Kaldahl’s car was so badly covered with the stuff, a regular car wash did nothing to remove it. She spent $250 Thursday getting the car professionally cleaned. She thinks someone should pay for the damage.

“Absolutely. Not only pay for it but, we should know what it was, know what it was that hit us,” she said.

Dallas firefighters responded on Thursday. A statement from Dallas Fire-Rescue spokesman Jason Evans said DFR could not verify the source and called police.

People at another business nearby found a bag on the ground of purple powder that’s believed to be fire retardant material that may have fallen from a plane.

A statement from Dallas police said they are now investigating.

“I’d love to know what they find out,” Kaldahl said.

Planes fly over those businesses all the time but people there said there’s never been a problem before.

”We've been in this building for 10 years now. Never had anything like this happen. We went through the tornadoes in October, had a lot of damage down here and now this. Maybe we need to move,” Gunn said.

On Friday, it was an unsolved mystery on Andjon Drive.