BAUDETTE, Minn. (AP) — A passenger died after a commercial transport vehicle crashed through the ice on a Minnesota lake. Meanwhile, state officials are warning people to be wary of ice that is unusually thin for this time of the winter.

The transport vehicle, commonly known as a “bomber,” crashed through the ice Thursday morning on Lake of the Woods, the Minneapolis Star Tribune reported. The body of a male passenger was recovered about seven hours later by a dive team, the sheriff’s office said.

The victim’s name has not been released.

Paul Colson, owner of Jake’s Northwest Angle Resort, told the Star Tribune that a neighboring resort was operating a snow bus when it broke through the ice. Colson said around five or six passengers were able to escape with the help of the driver.

Bombers are equipped with caterpillar tracks. They are used on the American side of the lake to haul customers to and from ice fishing locations away from shore.

The Minnesota Department of Natural Resources said ice conditions have deteriorated in recent days. Beltrami County Sheriff Jason Riggs said on Facebook that “few, if any, areas of the state have the ice thickness necessary” to hold structures placed on the ice for fishermen, often known as wheelhouses.

Riggs, whose county includes the popular ice-fishing destination Upper Red Lake, said conservation officers and county deputies have responded to several recent incidents of vehicles and wheelhouses falling through the ice. That includes three rescues on Upper Red Lake, Riggs said.

Temperatures in northern Minnesota are expected to drop, but officials warned that it will still take several days for the ice to thicken.