The dark of night still draped San Jose Mineta International Airport when a 15-year-old boy from nearby Santa Clara made his way on to a secure airport ramp and toward a Hawaiian Airlines Boeing 767, then disappeared.
The slight teenager, first seen on a security camera video, would not appear again until late Sunday morning, when airline workers spotted him, 2,350 miles to the west, wandering on another tarmac, this one at Kahului Airport on the island of Maui.
In the interim, authorities say, the boy survived a perilous 5 1/2-hour odyssey— weathering frigid temperatures, oxygen deprivation and a flight compartment unfit for human habitation — as he traveled over the Pacific Ocean in the wheel well of a Hawaiian Airlines jet.
The transoceanic misadventure left authorities questioning both how the stowaway so easily gained access to the jumbo jet and how he survived with so little apparent trauma.
Aviation security experts said it is troubling that the teenager was able to bypass security and get to the plane undetected. But they said it remains unclear whether human error allowed for the breach or if there is a much more serious gap in security.
The Transportation Security Administration planned to meet with law enforcement and airport officials to review security after the incident, which experts noted could have been catastrophic if the stowaway had been armed with explosives.
Authorities said the teenager apparently had no malicious intent toward the Boeing 767 or toward the 212 passengers and 10 crew members who rode aboard Hawaiian Airlines Flight 45, which took off at 7:55 a.m. Sunday.
Shortly after the plane landed at 10:31 a.m., airline workers spotted the boy and reported him to airport security. A Maui News photo showed him some time later sitting upright on a gurney, attended by paramedics, apparently alert and showing no obvious signs of his ordeal. He wore a sweatshirt with an orange hood.
Authorities said the temperature at the jet's cruising altitude of 38,000 feet could have dropped to 50 degrees below zero or less. Oxygen would have also been in painfully short supply at that height, about 9,000 feet higher than the summit of Mt. Everest.
FBI spokesman Tom Simon said that the boy apparently had been unconscious for the "lion's share of the flight."
Such ordeals do not usually end well. Those who do not fall to their death can be crushed by landing gear, or succumb to cold and lack of oxygen. Federal Aviation Administration records show that of the 105 people who stowed away on flights around the world over the last 67 years, 25 lived through the ordeal, a survival rate of 23.8%.
"He must have had the four-leaf clover in his hand or something," said Jeff Price, an aviation security expert at Metropolitan State University in Denver.
Armand Dorian, a Los Angeles doctor who treated a high-altitude stowaway survivor in 2000, said the teen's survival over the weekend was not as surprising as his seemingly unblemished condition.
For the minority of stowaways who survive, "the planets align," said Dorian, an associate clinical professor of emergency medicine at USC/Verdugo Hills Hospital. For the lucky few, "the need for oxygen declines as the body cools. It's exactly like the concept of cryogenic freezing…. The boy's body went into a frozen state."
When Dorian treated another wheel-well stowaway in 2000, the patient suffered much more obvious trauma. That victim, in his 20s, crumpled onto the tarmac at Los Angeles International Airport after a 7 1/2-hour flight from Tahiti. His body core temperature had dropped to 79 degrees, which would normally be fatal, according to accounts at the time.
Dorian recalled that the patient had to be placed on a ventilator and pumped full of warm fluids via tubes inserted in his chest. The doctor said that the 15-year-old's unscathed appearance after landing in Hawaii made him a skeptic about how, or where in the plane, the teenager actually traveled.
The FBI and Hawaiian Airlines officials said, however, that they were convinced the teen had made the trip in the wheel well, which is not heated or pressurized, like the airliner's main cabin.
Experts had no trouble imagining much more severe outcomes for Flight 45. "People go over the fence, they're caught. But he got all the way to the aircraft," said security expert Price. "The question it brings up is: What's to stop somebody from putting a bomb on the plane with the same method?"
Brian Jenkins, an aviation security expert at Santa Monica-based Rand Corp., said it's unclear whether an adequate security system was poorly monitored, or whether safeguards need to be revamped entirely.
"If he was on the camera, why wasn't there a response? Was no one watching the monitors?" Jenkins said. "The first question will be, 'Gee, the cameras work, the response didn't. Was it just missed and they went back and searched through that time frame and oops -- there he is?'"
Though the wayward teenager was probably guilty of criminal trespass, the San Jose Police Department had no intention of pursuing criminal charges, according to FBI an official also following up on the case.
Little is known about why the teenager became a stowaway.
An FBI official told the Associated Press that the boy had run away from his family after an argument. But a woman who identified herself as the teen's older sister told an NBC affiliate that was not the case. The various agencies investigating said it was not even clear that the teenager knew where the jet was headed.
Airport personnel in Hawaii said they had turned the boy over to the state's child protection office, which said it was preparing to return the boy home. Dorian said the unknown traveler's immediate good fortune does not mean he is home free.
He estimated that the boy's heart rate could have dropped as low as 10 or 12 beats a minute. He said doctors will have to keep an eye out for longer-term symptoms such as headaches and depression, which might not emerge for months.