Winter weather conditions have forced the National Park Service to suspend the search for a small plane that crashed into Lake Clark with four aboard/NPS

Deteriorating weather conditions led the National Park Service to suspend the search for a missing single-engine plane that went down into Lake Clark at Lake Clark National Park and Preserve in Alaska with four aboard.

"Persistent ice fog over the lake has hampered search efforts. Winter conditions, including ice in portions of the lake, prevent the use of the Park Service's larger boats appropriate for operation on the lake," the Park Service said Monday. "Items found on Thursday and Friday confirm the plane crashed in the lake."

The temperature Monday morning was 7 degrees, with foggy conditions. Efforts to search Sunday were called off when fog prevented an Alaska State Trooper helicopter from taking to the air. Last Friday, searchers recovered the co-pilot seat and all three wheels of the plane, the Park Service said.

The Park Service asked that any pilots flying over the 43-mile-long lake in the future report any debris, a description of the item, and a GPS point to staff at 907-781-2218.

The plane, a Piper PA-28, went missing last Wednesday during a flight from Port Alsworth inside the national park to Anchorage, Alaska, roughly 175 miles to the northeast. Debris was spotted in the park's namesake lake the next day.

Aboard the plane were pilot Kyle Longerbeam, 25; Scott Blom, 45, and his children, Zach Blom, 13, and Kaitlyn Blom, 14, all of Port Alsworth, according to the Park Service.