(Stephanie Joyce/KUCB)

As winter comes to a close, drivers in Unalaska have been struggling to avoid potholes. Now, in a slightly ironic twist, a city loader got stuck in the largest pothole of all on Wednesday while doing road maintenance.

A Department of Public Works employee was removing snow from the Unalaska City School parking lot around noon when the dirt beneath the loader caved in, leaving its tire stuck in a hole approximately five feet deep and four feet long. When the dirt collapsed, it revealed a man-made structure covered in broken pieces of rotten wood.

While there was some initial speculation that the hole led down to a World War II-era tunnel, it appears that it just opened up onto an unused septic tank.

Mike Whitman is the chief vehicle mechanic for the city, and he says it’s the first time he’s seen something like this happen in Unalaska.

“The dirt was clear up against the tire when I came here at lunchtime, and the rest of this fell and it just disappears down their into the hole,” says Whitman.

Whitman adds that the ground likely sunk in because of the mixture of wet and cold weather the island has been experiencing.

A road grader successfully pulled the stuck loader out of the hole later in the afternoon. The Department of Public Works is currently working on repairs to the parking lot. The city has not yet estimated how much it will cost to fill the hole.

Stephanie Joyce contributed reporting to this story.