About 4,000 DACA recipients who tried to renew their participation in the program before October 5, 2017 missed that deadline.

Some of those applications — no joke — got lost in the mail.

Twenty-six-year-old Osman Enriquez, a stone mason and construction worker in Lancaster, Pennsylvania, is one of them. Last week, that postal carrier snafu landed him in immigration detention.

“Last Monday, we were going to work. It was eight in the morning,” he said in Spanish, standing outside of U.S. Immigration and Customs Enforcement (ICE) offices in Philadelphia, with his fiancee, Sindy, and infant son, Jayden.

Enriquez, who is originally from Jutiapa, Guatemala, had been driving himself and three other men to work in a Chevy truck with expired registration. Pennsylvania State Police officers stopped them and discovered that his drivers’ license — which is tied to DACA — had also expired. After that, “it took about 40 minutes for Immigration to arrive,” he said.

In a statement, Pennsylvania State Police spokesman Ryan Tarkowski said, “Mr. Aroche Enriquez was cited for operating a vehicle without a valid license and issued a warning for expired vehicle registration.” All four men had outstanding detainers, which warranted a call to ICE, according to Tarkowski.

Enriquez spent four days in immigration detention at York County Prison, where ICE holds immigrants it plans to deport.

His case highlights how tenuous life can be for DACA recipients as the Trump administration moves towards ending the program in March. Created by an executive order issued by President Obama, Deferred Action for Childhood Arrivals (DACA) provides a temporary reprieve from deportation for some immigrants whose parents brought them to the US illegally as children. It allows recipients, many of whom have lived in the US for the majority of their lives, to work legally and obtain driver’s licenses. As of March 5, 2018, President Trump says DACA applications won’t be renewed unless Congress acts to make the program permanent under federal law, rather than executive action. Democrats hoping to protect these immigrants in the long-term say many recipients like Enriquez could suffer consequences before that March end date.

In a statement, ICE spokesman Adrian Smith said the agency decided to release Enriquez from detention after reviewing his case. Another government agency, U.S. Citizenship and Immigration Services (USCIS), processes applications for DACA and other programs that protect people like Enriquez from deportation. After the postal service’s role in delaying DACA applications came to light, USCIS announced it would allow those recipients to reapply for renewal.

However, delays in that reapplication process have frustrated immigrants’ rights advocates, who say it leaves some vulnerable to arrest in the meantime.

“They’re in limbo,” said Bilal Askaryar, media associate with Church World Service, an immigrant and refugee advocacy group which has represented Enriquez.

Askaryar assembled about 15 people to cheer on Enriquez during his first visit to ICE since his incarceration. Volunteers like Sister May, a nun with the Sisters of Mercy, chanted slogans and prayed for Enriquez and his young family.

“It’s so unfair to see people living in fear and anxiety,” she said, standing outside ICE’s 8th street office in Philadelphia.

According to Enriquez’s attorney, Andy Mahon, ICE has been “fair and reasonable” since its officers learned the details of his case. But his arrest highlights the confusion and uncertainty facing DACA recipients.

“It’s one thing when it’s on paper, that we’re repealing DACA,” he said. “It’s another thing when you see people affected by it.”

Enriquez, who has lived in Lancaster for 11 years, said the arrest pushed him to move up a big life decision: proposing to his now-fiancee, who has legal residency in the U.S.

“In my mind, I had the plan to do it on his birthday,” said Enriquez, gesturing to Jayden, who will turn one on Wednesday. “And when I was in jail, I was like, ‘No, I’m not going to make it.'”

Two days after his release, Enriquez proposed. She said yes.