France is calling her a miracle. After 11 p.m. on Wednesday, at a gruesome murder scene on a forest road in the French Alps, investigators were surprised to find a small child, alive, buried in the chaos. Hidden under a murdered woman's skirt and luggage in the backseat of a bullet-riddled BMW, a four year-old girl was found alive eight hours after the vehicle was discovered. But the gory attack that left four dead in a British-plated car in the hills above Lake Annecy remains a mystery without clear motive in France.

At 3:48 p.m. on Wednesday afternoon, a British cyclist called for help near the French village of Chevaline. In an area popular with hikers, the former Royal Air Force member had ridden up to the end of a mountain road where he witnessed a seven year-old girl collapse alongside an idling BMW station wagon with British license plates. French authorities say the cyclist assisted the girl, called for aid, and then discovered another cyclist lying dead on the ground beside the car. He recognized the cyclist as a rider who had overtaken him on the climb about 30 minutes earlier—now shot in the head. The RAF-trained cyclist then broke the right-hand driver's side window to cut the motor, discovering three bodies inside the car—two with visible wounds to the head—a man in the driver's seat and two women in the backseat, including an older women, believed to be a mother and grandmother. French authorities on Thursday saluted the cyclist-witness's sangfroid under the circumstances.

Law enforcement called to the scene on Wednesday would later learn that the group—authorities will not confirm that the women and the driver belong to a single family—allegedly had been vacationing in a caravan at a nearby campground since Monday. At 11 p.m., eight hours after the vehicle's discovery, a campground neighbor who said he had chatted with the English-speaking family signaled that there had been a second child with the group. Ten minutes after a search began at the scene for another child, a four year-old was found inside the car. Authorities say she had remained soundless for eight hours while they explored the crime scene without displacing the victims and went undetected even by the heat sensor-equipped helicopter that had scoured the area. Investigators pulled her out from under the legs of one of the dead women in the backseat. The girl then smiled at the gendarmes, or military police, who rescued her, evidently unaware of the extent of the tragedy around her, and spoke to them in English.

Annecy Public Prosecutor Eric Maillaud said in a press conference Thursday that the burgundy-colored BMW had not been sprayed with bullets, contrary to earlier reports. At least 15 shells were discovered at the scene—likely from one or more automatic weapons, although Maillaud would not speak to the caliber—but only some windows had been shot through while the car's bodywork was entirely intact. At least three of the four victims had been shot in the head. Asked whether the murders appeared to be professional hits, Maillaud bristled, saying only for now that they were "an act of extreme savagery." Investigator Lt. Col. Benoît Vinnermann, added that the grim crime scene "goes well beyond television fiction."

The first body found, the dead cyclist, has been identified as 45 year-old Sylvain Mollier, a local man whose worried wife had called gendarmes and provided a photo. But the identity of the family has not been confirmed. French authorities—with help from their British counterparts—have traced the vehicle to an Iraqi-born man who has lived in Britain since at least 2002. Media reports have named the car's owner as Baghdad-born Saad al-Hilli, 50, of Claygate, Surrey, employed in the aeronautics industry—although Maillaud would not confirm the name, saying it was not yet certain that the car's owner was the same man driving the car. French authorities would only say that the passport number of the man to whom the BMW is registered matches the passport number provided to reserve the family's spot at the nearby campground. A Swedish passport was found in the possession of the older murdered woman and authorities say an Iraqi passport was also identified.

Neither of the children discovered at the scene have been thoroughly questioned by police. The seven-year old girl was flown via helicopter to the hospital, suffering cranial fractures and an apparent gunshot wound to the shoulder. She has already sustained surgery and will be operated on again before police can speak with her. The four year-old girl was found to be in good health—“physically," at least, Maillaud emphasized. But the public prosecutor stressed her young age to temper expectations about her testimony—although he did confirm reports that the young girl had heard cries.

As the investigation continues, French law enforcement says they are excluding no trails of inquiry and have made no secret the motive has yet to come to light. Lt. Col. Vinnermann noted that it isn't even clear at this stage if the cyclist's death was collateral damage to the attack on the family, or vice versa, or whether both were collateral damage for something else entirely. The public prosecutor acknowledged there had been eyewitness reports about vehicles—in particular, an SUV—that raised suspicion in the area around the time of the murders, but declined to say more. The last of the bodies were removed from the car on Thursday and autopsies will be conducted on Friday. The British Ambassador to Paris traveled to the area on Thursday afternoon. French President François Hollande happens to be visiting London on Thursday, scheduled to meet with Prime Minister David Cameron and attend Paralympics events, just as headlines on the Alpine murders stun Britain.