From his small mountain town in the Ecuadorian Andes, Darwin Cabrera made the long, dangerous journey through Central America and Mexico and finally across the Rio Grande, into the United States.
But on June 3, 2014, just after he crossed illegally into El Paso, Texas, Border Patrol agents spotted him with other crossers on Sixth Street.
As they gave chase, the 18-year-old dove into one of the canals flanking the US side of the river. He didn't surface.
Two days later, Border Patrol agents in a helicopter spotted his body, floating face down. El Paso police officers fished it out of the canal. The local medical examiner recorded the details of the death.
But even though Border Patrol agents saw him go in and saw his body come out, his death did not count in their eyes. The agency's official tally of border-crossing deaths in their El Paso sector that year: Zero. After CNN contacted sector officials with a copy of the El Paso medical examiner's report, they acknowledged the error and said they would add the death to their records.
For 20 years, as part of its mission, the Border Patrol has been tasked with tracking and trying to prevent border-crossing deaths. But an investigation by CNN has found that the agency has been, at best, haphazard about tracking and recording deaths. Despite telling Congress and the General Accounting Office it would provide comprehensive accounting of migrant deaths, it has failed to do so. It has excluded fatalities reported by other law-enforcement agencies, while claiming to include them, and neglected even to count some deaths directly witnessed by Border Patrol agents.
Over the 16 fiscal years ended last September, CNN has identified at least 564 deaths of people crossing illegally in the border region, above and beyond the Border Patrol's tally of 5,984.
Those uncounted deaths were identified through a review of federal, state and local records and databases, and interviews with medical examiners, pathologists, sheriffs and justices of the peace along the border. It is by no means a complete count, and there are strong indications that the actual toll could be thousands higher.
More than half of the uncounted deaths identified by CNN happened in the past four years. Those figures mirror a recent investigation by the Arizona Republic, one of a set of pieces on border conditions that won the 2018 Pulitzer Prize for explanatory reporting. That story documented a significant undercounting of migrant deaths from 2012 to 2016.
The effective erasure within federal statistics of Cabrera's death and so many others has helped minimize the magnitude of the humanitarian crisis associated with illegal crossings. Downplaying the death toll also makes it harder for the United States to assess the full impact of a border policy, in place since the mid-1990s, that uses barriers and other enforcement tools to push migrants to more remote, deadlier crossing points.
That policy was designed to deter crossers, but, as officials realized nearly from the start, its primary impact has been to make the journey far more deadly. Today, experts who study the border fear that deportation and border enforcement strategies being pursued by the Trump admininstration may drive deaths even higher -- making it all the more important to accurately track fatalities.
Carla Provost, the acting chief of the Border Patrol, declined interview requests from CNN. She referred questions to Benjamin Huffman, the Border Patrol's chief of strategic planning and analysis.
Huffman acknowledged that the agency's death tally is incomplete. He said Border Patrol may exclude deaths from local agencies because it doesn't trust their standards. "How other people make these determinations (of what constitutes a migrant death) may not be consistent with what we've done," Huffman said.
But CNN found that the Border Patrol has made little effort to count deaths beyond the ones they encounter. Medical examiners and sheriffs agreed that the Border Patrol doesn't ask for their numbers. And 10 Border Patrol agents and supervisors across the southwestern border and in Washington told CNN that they account only for migrant deaths that Border Patrol agents are directly involved in handling. They don't include other deaths reported by landowners or others to local law enforcement.
"We've only ever counted what we find," said Felipe Jimenez, an agent in the Border Patrol's Tucson sector since 2009. He said that, as an emergency medical technician, he has been involved in many rescues and encounters with deceased migrants.
"The ones we find are our official number. Since I've been in, it's just been what we encounter," said Chris Cabrera, a spokesman for the Border Patrol agents' union who has worked as an agent in the Rio Grande Valley sector since 2001.
Huffman was unable to explain why the Border Patrol's reports to Congress have said it is reaching out to other agencies for death counts when its own agents and supervisors said they are not.
It's impossible to know exactly which deaths are being included in the Border Patrol's count, since their reports offer almost no specific details. The agency said it occasionally adds migrant deaths outside the region it covers. For example, Huffman said they included the well-publicized deaths this past July of 10 migrants trapped in a sweltering tractor-trailer in San Antonio, even though it was Immigrations and Customs Enforcement that responded to the scene. Even with those additions, though, the agency's numbers fall short of CNN's count of known migrant fatalities.
Rep. Henry Cuellar, D-Texas, a member of the House Appropriations Homeland Security subcommittee, said lawmakers rely on correct information to make border policy. "The Border Patrol's mission is to keep us safe, number one," Cuellar told CNN. But, he said, having an accurate picture of where and how many people are dying and being rescued also helps reduce the dangers -- both for border crossers and for the agents who risk their lives to save them.
Cuellar has heard from constituents who are concerned about the death toll. Last year, he said, he added language to the House appropriation bill requiring the Border Patrol to provide greater detail on how it tracks border deaths and what it does to prevent them.
"Folks brought up the issue about 'are we doing enough to have the Border Patrol identify and count deaths along the border,'" said Cuellar. When he added the language, he said, "we thought it was sufficient. ... These are issues I want to bring up and ask them if we should be changing the protocol. We all want to see accurate counts."
The surge in crossing deaths began after a 1994 change in the Border Patrol's strategy. That year, the Border Patrol decided to begin building barriers in urban areas such as El Paso, to push border crossers out into more remote and dangerous terrain.
Policymakers believed that once people saw how perilous the new routes were, they'd stop trying, said Doris Meissner, then-commissioner of the Immigration and Naturalization Service, which at the time included the Border Patrol.
But within a year or two, based on how many people agents continued to apprehend, it became obvious that the dangers weren't deterring crossers. And the number of migrants dying on the border had jumped from dozens a year to hundreds. "The deaths weren't contemplated," Meissner said. "Obviously, one can't be anything but regretful about the deaths."
Meissner said the agency had "quite a discussion" about what to do. "But it wasn't, 'Oh dear, we need to change the strategy,' It was, 'Are there things we can do to mitigate what's happening?'"
So in 1998, the Border Patrol launched the Border Safety Initiative, a set of measures to warn migrants about risks, rescue those in trouble, and quantify border-crossing deaths. But the initiative left it up to leaders in each of the Border Patrol's nine Southwest border sectors to decide which bodies to count and how. By the mid-2000s, policymakers on both sides of the aisle were asking questions about the rising death toll. That led Senate Majority Leader Bill Frist, R-Tennessee, to ask the Government Accountability Office to look into what the Border Patrol was doing to track and prevent deaths.