Nearly 10 years after an Air France Concorde crashed and burned near Paris, killing all 109 people on board and four on the ground, a trial began this week in France to determine who will be held responsible.

Six defendants have been charged with involuntary manslaughter — two maintenance workers employed by Continental Airlines who were involved in installing a titanium strip that fell off a DC-10 onto the runway, allegedly causing the damage to the Concorde that led to the crash; two former engineers at Aerospatiale, the company that built the Concorde; a former official of the French civil aviation authority who oversaw Concorde operations; and Continental Airlines itself.

All of the accused have denied the charges. A French investigation found the installation of the metal strip on the Continental jet did not meet FAA standards. Continental’s lawyers say they have witnesses who will testify that the Concorde engine was already on fire before it struck the debris.

“I question the independence of the investigators, I question those who did not want the truth, I question Air France, and it is evident that on July 25, 2000, the Concorde should never have been allowed to take off,” said Olivier Metzner, Continental’s lawyer. He said the supersonic jet suffered from flaws that were covered up in an effort to protect the “image of France” that the Concorde represented. The trial is expected to take about four months.