Mystery In The Details

The crash is part of popular legend now. The 13th pillar in the Alma tunnel has become a place of morbid pilgrimage: a way station in the re-enactment of Diana's life and death. But a thousand imponderables lie behind the tragic tale of that car accident on Aug. 31, 1997, that also killed her lover Dodi Fayed and driver Henri Paul. French authorities still have no clear answers to many vexing questions. They say they have definitively ruled out the possibility of a conspiracy, and now consider the crash an accident owing mainly to drunk driving, excessive speed and a dangerous stretch of road. Yet many of the key mysteries are far from solved--and some troubling facts have emerged. Among them: the hastily rented black Mercedes S-280 may have had serious mechanical failures; and driver Paul's blood, apart from a high alcohol content, showed an abnormally high--and yet unexplained--level of carbon monoxide. A summary of TIME's findings:

--THE MERCEDES The gendarmes' specialized research unit will hand over its technical report on the Mercedes in late September, and sources close to the investigation indicate that they have found no major problems. That is surprising, because certain items in the dossier, and the analysis of outside experts, point to some potentially serious malfunctions.

The front air bags, which probably saved bodyguard Trevor Rees-Jones' life, may also have provoked the final crash. According to the report of a trauma expert at La Pitie-Salpetriere hospital, the nature of Rees-Jones' facial injuries suggests that the air bags may have inflated with explosive force before the Mercedes struck the 13th pillar. That raises the possibility that the initial brush with another car, the mysterious Fiat Uno, may have triggered the deployment of the air bags, stunning and blinding Paul at a critical moment. At the request of Rees-Jones' French attorney, investigating Judge Herve Stephan ordered a technical report on the air bags last December. The resulting document is inconclusive but does not rule out this hypothesis. Sources close to Rees-Jones say his lawyers may be preparing a damage suit against Mercedes-Benz based on this possible malfunction.

The car may have had other major flaws. The regular chauffeur of the Mercedes, Olivier Lafaye, testified that a persistent warning light on the dashboard indicated a problem with the antilock braking system and the brake linings. The manager of the Etoile rental company, Jean-Francois Musa, told investigators that he had checked with a Mercedes dealer and was told that it was a false alert due to "air bubbles" in the hydraulic-brake circuit. But the claim of air in the brake system, if true, is itself worrisome: automotive experts consulted by TIME say this could reduce the efficiency of the brakes.

Investigators have discovered another anomaly: the brake fluid contained 7.5% water. Since water is not normally present in the system, Judge Stephan has requested an expert report on how it got there and whether it could have caused the brakes to malfunction. Experts consulted by TIME say this amount of water could cause corrosion and rust that might impair or even disable the brakes.