A 12-inch hole in the fuselage that forced a Detroit-bound Northwest Airlines flight to make an emergency landing in Buffalo last month could have been caused by baggage handlers in Syracuse, according to a National Transportation Safety Board report.

The preliminary three-page report does not assess blame or pinpoint the cause of the gash that forced Flight 1411 to make an unscheduled landing May 18 at Buffalo Niagara International Airport.

However, the report recites the circumstances surrounding the event and says "the height of the damage on the airplane was approximately the same height as the top of the cab of a baggage cart tug used by contract personnel to load passenger luggage onto the airplane."

The 12-by-5-inch hole was approximately six feet forward of the cargo door and was "consistent with the skin being damaged by a foreign object," the report said.

NTSB investigator Todd Gunther said the agency is looking into whether the ground crew reported any collision between their vehicles and the 38-year-old Douglas DC-9 plane.

The plane had completed an airworthiness inspection one day earlier, the report said.

The ground crew working in Syracuse for Northwest Airlines is employed by Air Wisconsin, the nation's largest independently held regional airline, which also provides ground handling services for United Airlines. Air Wisconsin spokeswoman Barb Jones did not immediately return a phone call seeking comment.

Northwest spokesman Roman Blahoski said the Minneapolis-based airline's preliminary investigation indicated the incident was the result of ground damage. The airline has no additional details to provide at this time, he said.

The NTSB will issue a final report on the mishap in six months, Gunther said. That report will be sent to the NTSB board, which will issue its findings on the cause 30 days later, he said.

According to the report, Flight 1411 was en route from Syracuse to Detroit and was 20 minutes into the flight when the flight crew heard a "loud pop" as the plane was approaching 19,000 feet.

The plane experienced a loss of cabin pressure and smoke filled the cockpit. The plane's oxygen masks automatically dropped as pilots made an emergency descent to 10,000 feet. The flight diverted to an emergency landing in Buffalo.

The airport went on alert, and the plane landed safely with 95 people aboard.

The hole in the plane's hull was found after it landed.

The episode is virtually identical to an incident two years ago in Seattle when an Air Alaska jet was forced to return for an emergency landing after a decompression episode caused by a 12-inch gash in the fuselage. A ground crew member had struck the plane with his loading cart but failed to report it because he said the damage did not seem severe.

In that case, a ground crew member was suspended, while others had to undergo safety training.