The Homeland Security (HSA) Department is being urged to allow thousands of beneficiaries of the Deferred Action for Childhood Arrivals (DACA) program to re-submit late applications, those applications untimely due to United States Postal Service (USPS) delays.

A group of 24 senators lead by Martin Heinrich (D-N.M.), which included Senate Minority Leader Charles Schumer (D-N.Y.) and Elizabeth Warren (D-Mass.), sent a letter to acting HSA Secretary Elaine Duke on Wednesday, saying they are “troubled” by reports that some DACA recipients’ applications were rejected due to postal delays.

One applicant’s lawyer said she sent a client’s application in mid-September, well ahead of the Oct. 5 deadline, and even sent it certified mail. The recipients were asked to reapply before the deadline of Oct. 5 if they wished to benefit from the program’s protections. According to The New York Times, the paperwork was mailed from New York in plenty of time.

Tracking data shows the envelope arriving in Chicago on Sept. 16, where it started “circling Chicago in a mysterious holding pattern,” the Times reports. “From Sept. 17 to Sept. 19, it was ‘in transit to destination.’ Then its tracking whereabouts disappeared until Oct. 4. Once again, it was ‘on its way.'”

It was eventually delivered on Oct. 6, one day late, and was rejected. According to the report, many more DACA applications arrived late, after being sent with plenty of lead time, advocates said.

“We are deeply troubled that despite the best efforts of many DACA recipients to submit their applications to DHS before October 5, the Department has rejected thousands of DACA renewal applications that arrived after the deadline,” the letter from the senators reads.

“We encourage you to weigh the life-changing consequences many will face in the absence of action by the Department.”

U.S. Citizenship and Immigration Services (USCIS), the agency that administers the DACA program, will not accept the late applications, regardless of the USPS’s admission that an “unintentional temporary mail processing delay in the Chicago area” may have caused some applications to be delivered late.

According to Vox, the “mysterious mail slowdown” may have affected at least 74 DACA recipients in the New York City and Chicago areas.

Additionally, Vox reports:

The plaintiffs in a lawsuit against the Trump administration (in a motion filed Tuesday in the Eastern District of New York and shared with Vox) allege that many more DACA renewal applications did arrive in a United States Citizenship and Immigration Services (USCIS) mailbox on October 5 — and were rejected as late anyway.

In interviews with the plaintiffs and with other immigration lawyers, Vox has confirmed at least 19 cases, at two of the three mailboxes that USCIS used to accept DACA applications, where applications were placed in the mailbox in the late afternoon or evening of October 5 but marked as “received” on October 6.

Vox estimates that a “substantial portion of the 4,000 DACA renewal applications the government says it received late” could have been affected.

DACA is a veiled amnesty program, implemented under the administration of former President Barack Hussein Obama. It offers recipients protection from deportation if they meet certain criteria.