PARIS (AP) _ The doomed Air France Concorde that killed 113 people left behind a trail of debris, including tire parts on the runway, as one engine caught fire and another malfunctioned, investigators said Thursday. They said the plane wasn't even able to lift its landing gear.

Those were among the details the French Transport Ministry released Thursday, two days after the supersonic plane, spewing huge flames from its tail, crashed into a hotel outside Paris. The new information emerged after officials decoded the two black boxes, which provide vital clues for accident investigators.

The ministry's assessment confirmed a total failure of engine No. 2 on the inside of the left wing, as had been presumed. But the assessment added that engine No. 1 right next to it also malfunctioned, losing some of its power during the short flight.

The statement said the pilot, Capt. Christian Marty, told the control tower after takeoff that he could not lift the landing gear. It said debris from the burning plane was found all along its short route, with parts of the tires left on the runway.

The ministry said it could take several days to complete the analysis of the 600 pieces of technical information on the recovered flight data recorder. They had to be analyzed and then compared with information decoded earlier from the other black box, the voice recorder.

Elsewhere Thursday, French and German officials and blue-uniformed airline crews joined weeping relatives of the crash victims for a memorial service at Paris' 18th century Madeleine church.

A steady stream of flowers arrived at the church as the building filled up with mourners, including somber-looking Air France crew members, some bearing the winged insignia of Concorde cabin crews. Tourists mingled with Parisians for a moment of quiet reflection before the start of the memorial for the victims, most of whom were German.

Jean Leprovost, a visitor from France's northern Normandy region, stopped by to pay his respects.

``It was a catastrophe. What can you say?'' Leprovost said. ``Everybody was affected by this all around France, even in the small villages.''

President Jacques Chirac, who did not attend the service, sent a large bouquet of pale pink roses and other flowers. Other more modest bouquets came from ordinary Parisians who wanted to show their sympathy.

Air France, which has promised to compensate victims' families, said Thursday it would pay an advance of $20,000 each to help cover immediate outlays, like funeral costs.

Meanwhile, French prosecutor Xavier Salvat said he had opened an inquiry into ``involuntary homicide and involuntary injury'' relating to the accident. Such an inquiry, which can last for months, will try to determine whether charges should be pressed and against whom.

Involuntary homicide in France is defined as a negligent killing punishable by up to three years in prison, or a $43,000 fine. The three judges in the case can call witnesses to determine the circumstances of the accident.

At the scene of the accident, workers finished removing the bodies of all 113 victims from the charred and blackened debris and transferring them to a morgue in Paris for the difficult process of identification.

French authorities trying to determine what turned the sleek delta-winged jet into a furnace that dropped from the sky were focusing on the mighty Rolls-Royce engines that power the world's fastest jetliners at twice the speed of sound across the Atlantic. Officials said the fire that consumed the Concorde seconds after its takeoff from Charles de Gaulle airport probably started in the No. 2 engine.

The investigation should focus on turbine blades that rotate and compress air inside both engines on the left wing, including the No. 2 engine, Raymond Auffray, an engineer and aeronautics adviser to Paris' Court of Appeal, said in the La Croix newspaper Thursday. Auffray's office is not connected to the inquiry.

The lack of control of the aircraft signals a ruptured turbine blade, Auffray said, which would cause the engine to destruct. The risk of such a rupture in normal circumstances is less than one in a billion for each hour of flight, so Auffray did not exclude the possibility of ``intruding objects'' in the engine.

Air France said mechanics had worked on engine No. 2 just before the takeoff. But government officials said it was too early to say if the repairs were linked to the accident.

Le Figaro, meanwhile, reported investigators were not ruling out the possibility of human error. The Liberation daily also cited Andre Turcat, a longtime supersonic pilot, as saying the pilot's decision to head toward nearby Le Bourget airport instead of returning to Charles de Gaulle was ``imaginable but risky.''

Video shot by the wife of a Spanish truck driver from a nearby highway captured the disaster. Like a monstrous, wounded bird, the great white plane struggled to gain height as a bubbling, blazing spout of flame and black smoke bellowed behind.

The plane dived into the Hotelissimo in Gonesse, a gritty industrial suburb north of Paris, killing all 100 passengers, nine crew members and four people in the hotel.

Ninety-six of the victims were Germans heading for the vacation of a lifetime _ supersonic jet to New York, then a five-star cruise into the Caribbean, through the Panama Canal to Ecuador and, for some, a trans-Pacific voyage to the Olympic Games in Sydney, Australia.

Their deaths, which ended the Concorde's 31-year record of safe flying, united France and Germany in sadness and provoked speculation about the jetliner's future.

For more than a quarter-century, Britain and France boasted of the plane they jointly developed as a marvel ahead of its time. But Concorde has never been a commercial success. Before the crash only 13 were operated _ seven by British Airways, six by Air France.

All Air France Concorde flights have been grounded since the crash. Transportation Minister Jean-Claude Gayssot said Wednesday he hopes to authorize them to start again soon.

British Airways resumed Concorde flights from London to New York on Wednesday after initially canceling services following the crash.