She arrived at Portland International Airport on a warm summer evening, dreaming of craft beer, long hikes and the good company she was about to enjoy in the Pacific Northwest.

Instead, Cristina Alonso, a 22-year-old student from Spain, was detained by federal customs agents, placed in handcuffs and eventually jailed 90 miles outside of the city.

Nearly 20 hours would pass before an American friend could contact Alonso inside the Northern Oregon Regional Correctional Facility in The Dalles, where the young woman had already sobbed for hours and suffered panic attacks.

"It was hell," Alonso said Wednesday during a Google video chat interview from Spain. "They treated me like a criminal when I hadn't committed a crime."

The disturbing chain of events all stemmed from a minor mix-up on her travel documents, one that even federal officials acknowledge as "probably an honest mistake." From there, bad luck, bureaucracy and miscommunication kept her detained for roughly 48 hours before officials placed her on a flight back home.

The July incident spurred national headlines in Spain decrying Alonso's treatment and a local backlash after the ACLU of Oregon published an account last week.

"She was caught in this net designed to prevent another 9/11," said Jaime Ruiz, a spokesman for U.S. Customs and Border Protection. "It's a massive operation to keep everyone safe."

Mat dos Santos, legal director of the ACLU of Oregon, offered a different perspective. "There are horror and thriller movies made with a plot like this," he said. "Only they don't take place in a country like the U.S."

Alonso had planned to visit Oregon for several weeks during the summer, staying with a family she knew who lived in Corvallis.

Laurie Bridges, a librarian at Oregon State University, said she connected with Alonso through a friend during a visit to Spain in 2016. Following that trip, she and her husband hoped to find a native Spanish-speaker to help their 8-year-old son learn the language.

Bridges and Alonso struck up a friendship over email and the messaging service WhatsApp and soon began making arrangements.

The family agreed to pay Alonso $100 a week to ease travel costs and to show her around Bend and Seattle in exchange for Alonso teaching their son Spanish. Alonso would stay in the family's guest bedroom. Occasionally, she would babysit as well.

Bridges planned to pick Alonso up at the airport, she said.

"We were all thrilled," Bridges said. "We had everything down to the last minute and detail of Cristina's trip."

Alonso, an interior design student at CESINE University in northern Spain, had never traveled outside the European Union. The chance to practice English and sample more of Oregon's celebrated local beers — some of which she'd tried back home — was too good to pass up.

"I was so excited to have all of these new experiences in a country that wasn't my own," she said. "I'm very extroverted. I love people and I love to travel."

Alonso's Condor airlines flight from Madrid landed in Portland shortly after 7 p.m. July 5. Soon after, she texted Bridges a photo of the long line at U.S. Customs and told her host that she'd arrived safely.

The trouble started when a customs agent began to ask Alonso about her stay. As a Spanish citizen, she was allowed to visit the U.S. for tourism purposes without a visa, so she never applied for one.

But when the agent learned that Alonso planned to babysit and would also receive a small stipend from her hosts, the agent determined that her travel authorization was invalid.

Instead, Alonso was told she should have applied for the type of visa normally used by foreign au pairs or nannies. That visa, however, requires recipients to stay in the U.S. for 12 months. Alonso had booked a six-week round trip.

Regardless, the mistake meant that Alonso was now deemed inadmissible, said Ruiz, the Customs spokesman. Agency policy requires those barred from entering the U.S. at an airport to return to their country of origin on the same airline that delivered them, he said.

That presented problems for Alonso. The next flight on Condor — a German air carrier — to Madrid didn't depart for another two days. And customs officials don't have a place to house people overnight at the Portland airport.

So, they must go to a secure detention center outside an airport.

Alonso, who does not speak fluent English, said she had no idea that she was going to be sent back to Spain.

Around midnight on July 6 — roughly five hours from the time she first arrived in Portland — she was placed inside a government car, which then left the airport.

Still uncertain with where she was going, Alonso's anxiety blossomed into fear as the drive dragged on, she said.

"I started asking, 'Where are you taking me,'" she said. "And I thought, 'Is this like one of those movies where they take me out, toss me in a ditch and leave?'"

She eventually arrived at The Dalles jail, known as NORCOR, which has a contract with the U.S. Department of Homeland Security to house federal detainees.

Though she wasn't accused of any crime, Alonso was handcuffed when she arrived and searched. She then had a booking photo taken and was placed in an orange jumpsuit worn by other prisoners.

"She went through same procedural process when booked into the facility as any inmate," said Bryan Brandenburg, the jail's administrator.

The stress and mounting confusion soon became crippling, Alonso said. NORCOR officials gave her conflicting information, leading her to believe they were lying, she said. She suffered an anxiety attack. She struggled to eat to or drink.

Guards would check on her hourly during the first day.

At one point, Alonso asked when she'd be released and somebody told her she'd have to wait until the following day at noon. Alonso watched the clock. And when the time neared, she waited next to the door to her cell.

"I was like a puppy," she said.

She'd have to wait longer.

Meanwhile, Bridges, who had stayed the night in a motel near the airport, scrambled to track down Alonso. Customs officials wouldn't tell her where they'd taken Alonso because she wasn't the young woman's family or lawyer, she said.

It was only after she contacted the ACLU of Oregon that Bridges learned Alonso had been jailed at NORCOR.

"When I called the jail I was told point-blank, 'We don't let friends talk to prisoners,'" she said. "That's when I became completely panicked."

Bridges eventually reached Alonso at the jail through a pre-paid communications account offered to inmates. By then more than 20 hours had passed since Bridges had last heard from the student.

"She was literally in shock. She had been crying for a very long time," Bridges said. "I felt physically ill."

It would be about another 24 hours before Alonso was transferred out of the jail and back to the Portland airport to catch her flight home.

Back in Spain, her story generated widespread media attention. Newspapers quoted Alonso calling her experience in the U.S. "a nightmare" and "psychological torture."

Ruiz said a combination of unfortunate factors led to Alonso's hardship. Most foreign travelers who are denied entry to the U.S. are able to catch a return flight in far less time, he said. And in larger cities such as New York or Los Angeles, Customs and Border Protection also provides 24-hour detention facilities at the airports, often with couches, beds and televisions.

"It was a horrible set of circumstances for someone who was probably making an honest mistake," he said.

Ruiz wouldn't disclose how many foreign travelers are denied entry to the U.S. at the Portland airport, citing national security concerns. But he said the number was tiny. "It's safe to say that 99.9 percent of travelers pass through PDX with no issues," he said.

Alonso isn't the only one to be held NORCOR. At least two or three foreign travelers have been jailed there since July 2015, but never for more than 24 hours, Brandenburg said.

Among them was Alia Ghandi, an Iranian woman detained by Customs and Border Protection officials in March after she arrived in Portland on a tourist visa. She had planned to visit family in Washington County for a few weeks, her sister told local reporters at the time.

Ghandi, who is now seeking asylum in the U.S., spent less than a day at NORCOR before she was transferred to a federal immigration detention center in Tacoma. She was later released, pending a decision on her case.

Brandenburg said that the Alonso incident prompted NORCOR to no longer accept individuals denied entry — but not accused of any crime — by customs agents in Portland. It will now house only federal detainees who have been charged with a crime, are in transit to a federal prison or awaiting a hearing on immigration status or deportation, he said.

"A lot of people got upset about the situation and probably rightly so," he said.

On the ride back to the airport, Alonso said federal officials offered her food and drinks and even charged her phone so she could call her parents.

"It was idyllic," she said. "But that doesn't mean I won't denounce how they treated me before."

Although the ordeal left her with little, if any, desire to return to the U.S. soon, the Spanish student praised the host mother she never got to stay with.

"Laurie was fantastic," she said. "I love this woman so much and I don't even know her. I owe her everything."

Oregonian/OregonLive staff writer Eder Campuzano contributed to this report.

-- Shane Dixon Kavanaugh

skavanaugh@oregonian.com

503-294-7632 II @shanedkavanaugh