WASHINGTON -- Nearly a year before President Barack Obama declared a humanitarian crisis on the border, a team of experts arrived at the Fort Brown patrol station in Brownsville, Texas, and discovered a makeshift transportation depot for a deluge of foreign children.
Thirty Border Patrol agents were assigned in August 2013 to drive the children to off-site showers, wash their clothes and make them sandwiches. As soon as those children were placed in temporary shelters, more arrived. An average of 66 were apprehended each day on the border and more than 24,000 cycled through Texas patrol stations in 2013. In a 41-page report to the Department of Homeland Security, the team from the University of Texas at El Paso raised alarms about the federal government's capacity to manage a situation that was expected to grow worse.
The researchers' observations were among the warning signs conveyed to the Obama administration over the past two years as a surge of Central American minors has crossed into south Texas illegally. More than 57,000 have entered the United States this year, swamping federal resources and catching the government unprepared.
The administration did too little to heed those warnings, according to interviews with former government officials, outside experts and immigrant advocates, leading to an inadequate response that contributed to this summer's escalating crisis.
Federal officials viewed the situation as a "local problem," said Victor Manjarrez Jr., a former Border Patrol station chief who led the UTEP study. The research, conducted last year, was funded by the Department of Homeland Security and published in March. A broader crisis was "not on anyone's radar," Mr. Manjarrez added, even though "it was pretty clear this number of kids was going to be the new baseline."
Cecilia Munoz, Mr. Obama's domestic policy adviser, said the administration and key agencies had made adjustments over time to deal with the influx of children but then responded with urgency once federal officials realized in May that the numbers would far exceed internal projections of 60,000 minors crossing the border in 2014.
Revised Border Patrol estimates now suggest the number could reach 90,000 by the end of September.
Last month, Mr. Obama ordered an emergency response overseen by the National Security Council and the Federal Emergency Management Agency, and he asked Congress to approve $3.7 billion in emergency funds.
"What happened this year was ... off-the-charts different," Ms. Munoz said. "It was not the same pattern. We assumed a significant increase, but this was not the same kind of trend line.
"This trend was more like a hockey stick, going up and up and up," Ms. Munoz added. "Nobody could have predicted the scale of the increase we saw this year. The minute we saw it, we responded in an aggressive way."
But top officials at the White House and the State Department had repeatedly been warned of the potential for a further explosion in the number of migrant children since the crisis began escalating two years ago, according to former federal officials and other people familiar with internal discussions. The White House was directly involved in efforts in early 2012 to care for the children when it helped negotiate a temporary shelter at Lackland Air Force Base in San Antonio.
"There were warning signs, operational folks raising red flags to high levels in terms of this being a potential issue," said one former senior federal law enforcement official, who spoke on the condition of anonymity to talk candidly about internal operations.
The former official said the agencies primarily in charge of border security, Customs and Border Protection and Immigration and Customs Enforcement, were "ringing alarm bells" within the administration.
Meanwhile, top officials focused much of their attention on political battles, such as Mr. Obama's 2012 re-election and the push to win congressional support for a broad immigration overhaul, that would have been made more difficult with the addition of a high-profile border crisis.
"I don't think they ignored this on purpose, but they didn't know what to do," said Michelle Brane, director of migrant rights at the Women's Refugee Commission, which published a 2012 report highlighting the influx of minors. "For whatever reason, there was hesitation to address the root causes. I think the administration was dealing with it at a minimal scale, putting a Band-Aid on something they should have been thinking about holistically."
Until recently, the number of Central American children crossing into the United States illegally was below 5,000 a year and was not considered a major problem among the many issues federal agents were dealing with at the Mexican border.
In 2009-2010, law enforcement agencies cracked down on criminal cartels in the traditional border hot spots near Tucson, Ariz. By 2012, the Border Patrol and U.S. intelligence agencies began noticing a shift of activity to the Rio Grande Valley in Texas, one they had anticipated.
They also found that even as overall illegal immigration to the United States slowed, the number of adults and families entering illegally from El Salvador, Guatemala and Honduras began to grow rapidly. Many were fleeing increasing violence and impoverished conditions in their home countries, according to U.S. officials and human rights groups.
The number of Central American minors making the trip without their parents -- who are afforded greater protections under a 2008 U.S. anti-trafficking law -- was a subset of the larger phenomenon, officials said. "It was more than it had been, but it wasn't something that would cause you to sort of drop everything and say we're in a crisis," said a person familiar with internal deliberations.
In Texas and in Central America, officials viewed the situation with greater alarm. In April 2012, the first ladies of Mexico, Honduras and Guatemala voiced their concerns at a conference in Washington on unaccompanied minors. "The statistics are worrisome," said Guatemala's Rosa Maria Leal de Perez.
A week later, Texas Gov. Rick Perry, a Republican, wrote a blistering letter to Mr. Obama, citing a 90 percent increase over the previous year in the number unaccompanied minors arriving from Central America. If the president failed "to take immediate action to return these minors to their countries of origin and prevent and discourage others from coming here, the federal government is perpetuating the problem," Mr. Perry wrote. "Every day of delay risks more lives. Every child allowed to remain encourages hundreds more to attempt the journey."
Inside the Obama administration, officials at the Department of Homeland Security were focusing most of their efforts on adults. Janet Napolitano, then secretary of Homeland Security, implored her counterparts in Mexico to increase border security to reduce the flow. U.S. immigration and border patrol officials created new processing centers, according to current officials and others familiar with the issue.
By the time the team from UTEP arrived at Fort Brown to examine the problem in the summer of 2013, the churn of the young immigrants had far outpaced the government's capacity.
In its report, the UTEP team wrote that border agents were interested in setting up a "welcome center" overseen by the Department of Health and Human Services that would serve as a clearinghouse for the minors, freeing patrol agents to monitor the border.
The number of minors arriving illegally from Central America shot from 3,933 in 2011 to 20,805 in 2013. HHS had secured 5,000 beds across the country -- twice as many as the previous year -- but that wasn't enough. Immigration courts were backlogged. Border Patrol stations were overrun. Federal officials estimated that the total number of minors would soar to 60,000 in 2014.