A small passenger plane that crashed last month in Alaska, killing all 10 onboard, was nearly 1,000 pounds too heavy for the weather conditions, according to a preliminary report on the incident released Wednesday.

The National Transportation Safety Board says a commuter plane that crashed on sea ice off Alaska and killed all 10 people on board was half a ton overweight for the known or possible weather conditions in the area.

A Cessna plane that crashed while flying to Nome, Alaska, last month, killing all 10 people on board, was hundreds of pounds too heavy for icing conditions, a National Transportation Safety Board report says.