May 2, 2013 -- Within hours one day in April, two children went missing hundreds of miles apart from each other.
On the surface they appear to have little in common.
Angelo Messineo is a 16-year-old from Georgia. He was found alive on a horse farm four days after he disappeared from school on April 16. Alyvia Navarro, 3, of Wareham, Mass., was pronounced dead hours after she was reported missing, drowned in a pond near her grandmother's home, on the same day.
They are just two of the thousands of children who went missing last month.
But Angelo and Alyvia have one thing in common, and it's a trait shared with at least one child who goes missing every day in America. They are autistic.
Nearly half of all children with autism will run away and potentially go missing at least once before their 17th birthday, according to a study by the American Academy of Pediatrics. Of those who run away, what clinicians call "eloping," many will be found dead.
The numbers alone present a challenge for law enforcement authorities, who regularly rank searches for missing children among the most difficult work they do.
But finding children with autism -- who shirk when their names are called out, who run away at the sound of police sirens, who are afraid of the dogs sent to find them, and who naturally are comforted by burrowing and hiding -- makes a hard job even harder, investigators say.
One in 50 children is diagnosed annually with autism, a spectrum of neurodevelopment disorders marked by problems with social interaction and communication, according to data from the Centers for Disease Control and Prevention in Atlanta. As the number of children who are diagnosed increases, so too does the number of kids who run off, leaving rescuers to learn quickly how best to handle a unique set of challenges.
The stories of Angelo and Alyvia, and dozens of children like them, present two sides of a phenomenon still not entirely understood.
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On the one hand, autistic children are more likely to run away than unaffected children. When they do runaway, they are more likely to die than unaffected children. And more often than not, 91 percent of the time, those deaths are a result of drowning.
But what is so perplexing to researchers and rescuers are the stories like Angelo's. Stories of almost super-human rates of survival for young children with developmental disabilities, who manage to stay alive for days often in the wilderness and against staggering odds.
"It's a mystery," said Robert G. Lowery Jr. of the National Center for Missing & Exploited Children. "Time and again, we see cases where autistic children live longer and survive in harsher settings than unaffected children. We don't really know why. It might be that these children with autism have a diminished sense of fear, but it's astonishing."
Stories like Alyvia's are also all too common.
The 3-year-old girl was there, at her grandmother's side at their home at the Lakeside Trailer Park in Wareham, Mass., and a moment later she was gone. Twenty-five minutes later, her grandmother Valerie Navarro called the police. Police, fire, EMS, K-9 units and the nearby harbormaster began a search for the girl, who was discovered an hour later, according to Wareham police.
A patrol found the girl in a pond near her grandmother's home, and she was evacuated via helicopter to a hospital in Boston where she was later pronounced dead.
Girls More Likely to Die
Calls to Alyvia's grandmother Valerie Navarro were not returned.
Boys are four times more likely to be diagnosed with autism, but girls, like Alyvia, are twice more likely than boys to die after an elopement, according to Lori McIlwain, executive director of the National Autism Association, which tracks eloping incidents and deaths.
In 2012, 195 autistic children went missing, according to the autism association, which only tracks those incidents reported by the media.
Between 2009 and 2011, 91 percent of autistic children younger than 14 died in drowning incidents after elopements. More than two-thirds of those deaths occurred in small natural bodies of water like creeks, lakes, rivers and ponds.
"Oftentimes, children who go missing are low or nonverbal," McIlwain said. "But they know where a pond is. They see it from the car going to and from school every day, but they can't tell mom or dad that they want go to the pond and play. They think about it and when they have the chance, they bolt."
It's a story all too familiar to Beth Martin, a single mother with three kids, whose 7-year-old daughter Savannah drowned in a pond near her Lawton, Okla., home in 2011.
"My daughter loved Ramen noodles," Martin said, remembering the Sunday morning that her daughter died. "I knew I had exactly four minutes. Typically, she would stare for four minutes, watching the noodles cook. I popped my head outside to tell my oldest, who's 11, to watch my youngest, who's 2, because I was going to run to the bathroom. I thought it was safe to go to bathroom."
'I Couldn't Get Them Both Out of the Water'
Before the noodles finished cooking, Savannah and her younger brother were gone.
"They both were missing," Martin said. "I asked the oldest where they went, but he didn't know. I panicked and looked all over the house and yard. I kept calling their names. I ran to the highway and then to our neighbors to ask if they had seen them. I asked my son to wait by the house and he came running to say he could hear them screaming."
By the time Martin made it to the half-filled pond on the edge of her property, Savannah was under the water. Her younger brother, who had been wearing a padded bicycle helmet, was kept barely afloat by its buoyancy.
"I couldn't get them both out of the water. … I started to panic and the neighbor jumped in to pull them out," Martin remembered. "I just collapsed after that."
Martin was a conscientious mother. When Savannah was born, doctors told her that her daughter would never talk or say, "I love you, mommy." Martin worked with her religiously, and the girl had begun talking. She even knew the lyrics to her favorite Taylor Swift songs.
She had enrolled Savannah in kindergarten, registered her for swim lessons, was looking to install alarms in case she ever ran off, and made a point to teach her daughter the boundaries on the property.
"I thought I had spoken with all kinds of experts about raising a child with Savannah's needs. But I was never told about wandering or about the likelihood of drowning. No expert ever told me that," Martin said.
In that way, Martin is like the majority of parents raising children with autism.
Sixty percent of parents are unaware of the likelihood that their child will elope or the subsequent risks of death, according to a survey by the National Autism Association.
The National Center for Missing & Exploited Children works with law enforcement agencies across the country to train cops on how best to search for children with autism.
Deaths Are Quick and Quiet
"We make recommendations to law enforcement about things they should be doing immediately," said Lee Manning, a former Massachusetts state trooper and now a consultant for the National Center for Missing & Exploited Children.
"[Police] have to respond very seriously and not waste any time. One of the things we strongly recommend is to get first responders, even neighbors, dispatched to local bodies of water right away," said Manning a member of Team Adam, a nationwide rapid response team of retired cops that helps law enforcement on the most difficult missing children cases.
Tragedies like the deaths of Savannah and Alyvia rarely make the front pages of newspapers or the morning television programs.
Their deaths are quick and quiet. But there is another class of autistic elopers who beat the odds with such astonishing results that law enforcement officials and rescuers are studying them to learn how best to search for runaways in the future.
On the same day Alyvia went missing, so did Angelo Messineo.
Angelo is a 16-year-old boy with a severe form of autism. A ward of the state, he is nonverbal and prone to violent outbursts. He "bolted from school after some sort of incident" in Lithonia, Ga., according to investigators.
Police scoured the woods of DeKalb County, Ga., for four days with few clues. Angelo was found April 20 on a horse farm 14 miles from where he was last seen. He was identified by police after an altercation with other teenagers.
He was taken to a nearby hospital and treated for dehydration.
Calls for comment to the DeKalb County School District were referred to the National Center for Missing & Exploited Children.
'They Tend to Burrow Down and Hide'
Unaffected children tend to panic, they walk in loops, they take dangerous risks in an attempt to save themselves, but children with autism tend to "have a diminished sense of fear," Lowery of the National Center for Missing & Exploited Children said.
"There's a different search criteria for children with autism. They tend to burrow down and hide. We don't know if it's because they fear searchers or if it's a kind of game. They seem to realize the peril they're in," he added
Two of the largest missing children searches in recent years involved kids with autism.
In 2010, 11-year-old Nadia Bloom was found by a volunteer after spending four days in an alligator-infested swamp in Florida. She was dehydrated and covered in insect bites.
In 2011, the largest manhunt in Virginia history took place more than six days as volunteers and rescuers scoured a dense forest looking for 8-year-old Robert Wood Jr., who ran off while visiting a state Civil War park with his father.
Robert was found alive by a volunteer, who has remained anonymous even to the boy's family, in a quarry about a mile from where he went missing. When he was found, he was in a fetal ball and burrowed in the dirt.
The search for Robert has become an important model for rescuers who conduct searches for children with autism.
"We knew never to take him where there was a pond," his grandmother Norma Williams said. "Like many autistic children, Robert is fearless. He doesn't feel pain. He doesn't fear heights. He doesn't fear water, but he can't swim. He'll jump off just about anything."
Many of the things that attract autistic children, often to their demise, were in the park trails that connected to rivers, roads and railroad tracks.
For five nights, Williams camped outside the park in her truck praying and waiting for news of Robert.
"I dropped to my knees when they told me he was alive and an investigator helped to get me back up. I couldn't stop crying," she said. "Robert's feet were so swollen, his shoes were stuck in mud, he had curled up in a ravine when the temperature dropped and it began to rain."
Since his rescue, Robert's family has allowed the local sheriff to outfit him with a radio anklet similar to those given to prisoners on house arrest, so he can be tracked if he runs away in the future.
"People have to understand autistic children aren't like other children," Williams said. "They're special. They run when they want and do what they want. And just because they can't speak doesn't mean they're not thinking things.
"If you went to those woods, you'd see they're so dense the light doesn't come through. There's coyotes and snakes and spiders.
"How did he survive? How do they survive? If you don't believe in God, come see Robert."