When 10 smuggled migrants died in San Antonio from being trapped in a scorching hot semi truck with almost no air to breathe, the country was appalled.
But their deaths are just a fraction of how many people die each year trying to flee their homelands and sneak into the US.
Every year, hundreds of undocumented immigrants perish trying to make the journey. And virtually all of those deaths occur while being smuggled, Customs and Border Protection spokesman Mike Friel said.
Friel said virtually all those crossing the border illegally are led by smugglers. That's because cartels have a stranglehold on the Mexican side of the border and control much of the land, he said.
"There are very few people who attempt to cross on their own," Friel said, and virtually no one would "risk going against the cartel."
In the San Antonio case, one survivor said he was told by his smuggler "that people linked to the Zetas (cartel) would charge 11,000 Mexican pesos ($620) for protection," according to a criminal complaint against the truck driver.
Even if smuggled migrants survive the often oppressive conditions, their odds of getting apprehended by a border patrol agent are much higher than death -- about 1,270 times higher, as of last year.
As you can see, the number of apprehensions has fluctuated over the past 20 years. There are several contributing factors to this, Friel said:
In the 1990s, the border between Mexico and San Diego was extremely porous -- with up to 4,000 people getting arrested there each day. At the same time, there was a spike in border crossings into Arizona. Apprehensions then plunged after Operation Gatekeeper increased fencing along the border and added more technology such as ground sensors and cameras. A spike around 2003 coincided with the surge of a booming business: smuggling rings moving migrants en masse. A gradual decline started in the mid-2000s, after the Bush administration doubled the number of border control agents from 9,000 to 18,000.
This past year, the number of apprehensions has ticked back up. And more than 30,000 unaccompanied children were among them.
Not everyone crossing illegally from Mexico to the US is Mexican. In fact, a huge number of border-crossers are actually from Central American countries, data from the US Border Patrol shows.
Guatemala, El Salvador and Honduras -- all countries that are grappling with rampant poverty -- are among the primary countries of origin.
Many of the migrants who cross the border illegally willfully pay smugglers to do so and don't become victims of human trafficking -- the act of exploiting or coercing people into forced labor or prostitution.
So not all smuggled migrants are trafficked, and not all trafficking victims are smuggled migrants.
"Nevertheless, people who are smuggled can be extremely vulnerable to human trafficking, abuse, and other crimes, as they are illegally present in the country of destination and often owe large debts to their smugglers," the State Department says.
In recent years, the number of human trafficking reports have steadily increased, according research and data from the National Human Trafficking Hotline.
"Despite growing awareness about this crime, human trafficking continues to go under-reported due to its covert nature, misconceptions about its definition, and a lack of awareness about its indicators," the agency said.
What may be surprising is where the highest rate of human trafficking is found.
The National Human Trafficking Hotline shows most reports of human trafficking are from the border states of California (1,323 in 2016) and Texas (670 in 2016).
But when you divide the number of reports by the total population, the District of Columbia actually has the most reported cases of human trafficking per capita, according to data from the NHTH.
And smuggled children are certainly at risk for human trafficking, the United Nations' children's agency UNICEF and World Without Exploitation said in a joint statement.
"Smugglers also take advantage of children and their families by extorting them with threats and false promises," they said.