Vandals slashed the tires of 87 planes at Merrill Field in Anchorage early Thursday morning. Officials and pilots at the field say it’s the largest act of air travel vandalism they’ve seen in their careers.

Merrill Field Airport manager Paul Bowers said the vandalism likely occurred between 1:30 and 6:30 in the morning, but airport officials and police are still reviewing the security footage and have no leads on who did it. The only information he said he can share is that tires were punctured on 87 planes.

Bowers said during his more than 40 years working in aviation, he’s never seen an act of vandalism this large.

“There have been individual thefts and some vandalism, but I have never heard of the extent of vandalism that we’ve seen this morning anywhere on any airport, ever,” Bowers said.

Bowers said the security at Merrill Field is robust, with multiple security cameras and tall fences. The area is well-lit and normally air traffic controllers can see the field, but no one monitors the area 24-hours a day.

“It’s just… it literally shouldn’t have happened,” Bowers said.

Total cost estimates for the damage range from $150 to 250 thousand dollars. Individual tires range in price from $200-300 for smaller ones and $1000-2000 for the larger tires.