Amid a growing border crisis and news that the "mother of all caravans" is journeying north from Central America, President Donald Trump on Friday threatened to shut down the border to alleviate overwhelming stress on U.S. immigration resources.

But just how bad is the situation at the border? According to a new USA Today story detailing the situation, local officials say the crisis has entered unprecedented territory.

What are the details?

In Texas especially, "masses of migrants have been crossing the border in unprecedented numbers, overwhelming federal holding facilities and sending local leaders and volunteers scrambling to deal with the relentless waves of people," USA Today reported.

"It's staggering. Really, we've never seen anything like this before," McAllen City Manager Roy Rodriguez told USA Today.

The problem is not necessarily immigrants crossing into the U.S. illegally. Rather, migrants are applying for political asylum en masse, overwhelming U.S. immigration resources. Smugglers know the more people they bring to the border, the quicker the system will be overrun, forcing officials to release migrants into the general public while they await their immigration court hearings.

In fact, immigration shelters are so overcrowded in some areas that immigration authorities were recently forced to build a makeshift shelter under the Paso Del Norte International Bridge in El Paso, where they kept some migrants for up to four days.

U.S. Customs and Border Protection Commissioner Kevin McAleenan said last week that the border crisis has hit a "breaking point."

"That breaking point has arrived this week at our border," he said. "CBP is facing an unprecedented humanitarian and border security crisis all along our Southwest border."

Indeed, as Fox News noted, the Border Patrol is on pace for over 100,000 migrant apprehensions and encounters in March, numbers the U.S. has not seen in more than a decade. Last Monday alone, Border Patrol agents encountered an estimated 4,000 migrants along the entire border.

"We are doing everything we can to simply avoid a tragedy in a CBP facility," McAleenan said. "But with these numbers, with the types of illnesses we're seeing at the border, I fear that it's just a matter of time."

Only "legislative relief" will alleviate the crisis and "restore integrity to our immigration system," McAleenan said.