Skip to content

Explainer: Migrant Deaths at the Border

On June 27, 2022, 53 migrants were found dead of heat exhaustion after being trapped in a semitrailer truck near San Antonio, Texas. It was the deadliest tragedy in American history to take the lives of migrants seeking to cross the Southwest border, a moment which sparked concern and anguish from border communities, onlookers across the country, and policymakers in Washington, D.C.

But while the scale of the tragedy had never been seen before, death at the border has become all too common. Fiscal Year (FY) 2022 is on track to set a record number of migrant deaths (a record that had previously been shattered in FY 2021) and numbers have been increasing since at least the mid-1990s. In a July 2022 report, the International Organization for Migration (IOM) labeled the Southwest border the “deadliest land crossing in the world.”

This explainer will describe what we know about how many migrants die attempting to cross the Southwest border, the reasons so many lives are lost at the border, what is being done to prevent migrant deaths, and what more we can do to bring safety and humanity to the world’s most lethal land border.

How many migrants die each year attempting to cross the Southwest border?
Why are an increasing number of migrants dying at the border?
What does CBP do to prevent migrant deaths at the border?
What more should the government do to prevent migrant deaths?

How many migrants die each year attempting to cross the Southwest border?

Estimates vary and likely undercount deaths, but the IOM Missing Migrants Project recorded an average of 457 migrant deaths and disappearances each year between 2014 and 2021 at the U.S.-Mexico border crossing.

Since 1998, the U.S. Border Patrol has recorded an average of 364 deaths per year and more than 8,000 total migrant deaths along the Southwest border. However, these figures are almost certainly an underestimate. A 2022 Government Accountability Office (GAO) report found that “CBP has not collected and recorded, or reported to Congress, compete data on migrant deaths.” The report noted that the official tally was undercounting total deaths, flagging “data entry and recording issues” within CBP and stating that Border Patrol did not always include remains located by external entities such as state and local officials.

The IOM Missing Migrants Project, which began collecting data in 2014, is a more robust estimate because it also incorporates data collected by Mexican immigration authorities, county medical examiners, coroners, and sheriffs.

Chart: Estimated Migrant Deaths at the Southwest Border

Sources: International Migration Review (1999); U.S. Border Patrol data; IOM data

Why are an increasing number of migrants dying at the border? 

A combination of factors has led to increasing migrant deaths, including an overall increase in migration at the border, more extreme weather conditions in border regions, and an absence of options to migrate in a safe and orderly fashion. 

Migrants attempting to cross the Southwest border between ports of entry are often faces with difficult terrain and extremely dangerous conditions. The temperature in barren border sections of Arizona’s Sonoran Desert, for example, can reach over 104 degrees Fahrenheit in the summer and drop to below freezing in the winter. Concerning land crossing, IOM lists “harsh environmental conditions” as the leading cause of death on the Southwest border, although a majority of all deaths in the dataset have causes listed as “mixed or unknown.” According to a 2021 report in Science, an increase in extreme temperatures and weather events along the border are contributing to additional migrant deaths — particularly from dehydration.

The total number of migrants attempting to cross the border is one factor in the total number of deaths recorded each year. In recent years, the lingering effects of the COVID-19 pandemic has exacerbated existing push factors in migrant-sending communities, including pervasive gang violence, environmental disasters, economic dysfunction, and corrupt and illegitimate governments. The result has been very high (although not quite record-high) numbers of individuals arriving at the border and attempting to cross in 2020, 2021 and 2022. This is one reason for increasing numbers of recorded deaths, as well.

However, variations in migrant deaths do not always correlate with the number of migrants attempting to cross the border. A University of Arizona study documenting migrant deaths on the Arizona-Mexico border from 1990 to 2020 revealed that the “rate of undocumented border crossers has largely increased even as apprehensions have declined, which is a dynamic that suggests undocumented migration in Arizona has become increasingly more dangerous.”

One reason that migration has become more dangerous is that safer, more orderly pathways to cross the border have been restricted. In recent years, many migrants have been blocked from seeking asylum at official ports of entry (POEs) along the border, in part due to a still-active pandemic-era policy called Title 42. Thousands more have been required to remain in Mexico under the Migrant Protection Protocols (MPP) which was active in 2019 and parts of 2020 and 2022. Unable to seek asylum in the U.S. in an orderly or safe fashion, many migrants — even those only hoping to make claims for protection under U.S. law — are forced to hire smugglers and attempt the dangerous journey across the border without authorization.

More generally, U.S. border policy has relied heavily on “Prevention Through Deterrence,” a concept that was first officially implemented in 1994 that sought to decrease attempted border crossing by making the border as difficult and dangerous to cross as possible. There is little evidence these policies have effectively reduced attempted migrant arrivals, but deterrence continues to be a guiding principle for much of our border policy.

What does CBP do to prevent migrant deaths at the border?

Border Patrol has employed increasingly sophisticated methods to rescue migrants in distress, and Congress has shown a recent interest in appropriating funds to prevent migrant deaths. Still, an increasing number of deaths indicate existing efforts are insufficient.


Border Patrol Search, Trauma, and Rescue (BORSTAR) is a specialized unit within Border Patrol that is trained to prevent migrant deaths at the border. The unit was founded in 1998, as part of the creation of the Border Safety Initiative (BSI), an acknowledgement from CBP that more needed to be done to prevent needless loss of life at the border.

BORSTAR is currently comprised of 250 Border Patrol agents from all Border Patrol sectors. BORSTAR agents must go through a 400-hour training course that includes various search and rescue techniques and medical training. BORSTAR agents also receive 80 hours a year of additional emergency medical training and other trainings designed to improve their ability to conduct rescue operations. Many BORSTAR agents receive additional trainings in topics such as wilderness survival, advanced tactical medicine, water rescues, and cold-weather operations.

Search and Rescue Efforts

In Fiscal Year (FY) 2021, CBP agents conducted a record 12,833 search and rescue efforts along the Southwest Border. As of August 2022, Border Patrol has already conducted 18,897 search and rescue efforts in FY 2022.

Chart: Southwest Border Search and Rescue Efforts

Source: CBP Statistics

CBP also uses technology to assist in search and rescue efforts. Rescue beacons are tools used by Border Patrol in remote border areas to rescue migrants in distress. They are 30 to 40 feet tall, solar-powered, and satellite-connected. They are equipped with 9-1-1 cellular relay, a strobe light, and a multi-lingual instructional placard to help migrants alert border patrol personnel to a distress call.

As of 2019, there were 34 total rescue beacons situated in remote border areas. In December 2020, Congress passed the bipartisan Missing Persons and Unidentified Remains Act, which required the implementation of 170 rescue beacons across the border. CBP has reported new rescue beacons are being built in accordance with the law, but the current number of operational beacons is not clear.

Missing Migrants Program

The CBP Missing Migrants Program (not to be confused with the IOM program of the same name referenced above) was founded in 2017 to help coordinate efforts to rescue migrants in distress, to identify migrant remains, and to track data related to migrant deaths. The Missing Migrants Program has coordinated placement of rescue beacons and placards with details on how to call for help along the border and worked to improve coordination with other federal agencies and external entities.

What more should the government do to prevent migrant deaths?

Congress and the administration should invest more resources in personnel and technology designed to rescue migrants in distress. It should also take a more holistic view of preventing migrant deaths and create more humane and orderly paths for migrants to apply for asylum and other relief at the border.

  • Congress has appropriated more and more funding to U.S. Border Patrol over the past three decades, increasing its annual budget to approximately $5 billion and making it the single largest enforcement agency in the country. Congress and the administration should work to use more of these massive resources for rescue efforts, including by allocating funds for exploring new rescue technologies and increasing personnel and technology dedicated to migrant rescues. 
  • Specifically, Congress should appropriate funds to increase the number of Border Patrol agents with access to EMT training and to double the number of BORSTAR agents to 500. Congress should also fund CBP to roll out required rescue beacons more expeditiously, including by allocating the $2 million CBP requested for FY 2023 related to rescue beacon implementation.
  • Congress and the administration should also work to expand access to asylum at lawful ports of entry, allowing many migrants to request protection lawfully rather than be forced to hire smugglers and attempt the dangerous journey across the border only to turn themselves in to Border Patrol and request assistance. This effort should include winding down policies that prevent asylum seekers from requesting protection at ports and expanding capacity at ports of entry to process asylum seekers.
  • As it becomes increasingly difficult for migrants to cross the border, they turn to more sophisticated criminal networks for assistance to reach the United States. Transnational criminal organizations put profit over human life and lead to the abuse, exploitation, and even death of migrants. In combination with the above reforms, the U.S. should collaborate with federal and foreign partners to crack down on criminal organizations engaging in the smuggling of migrants.
  • Beyond expanding access and capacity at ports, Congress and the administration should consider creating additional worker visa programs or otherwise expanding U.S. visa pathways to respond to U.S. workforce shortages and encourage more lawful, orderly migration.
  • External entities like academics and nonprofits have dedicated significant resources and expertise to documenting and preventing migrant deaths. The CBP Missing Migrant Program should work to improve coordinate with and support for these entities.

The National Immigration Forum would like to thank Gilberto Calderin, Policy Intern, for his extensive contributions to this explainer.


Related Topics


Download Resources

Learn More

Read more about Bill Analysis: The Missing Persons and Unidentified Remains Act

Bill Summary

Bill Analysis: The Missing Persons and Unidentified Remains Act

Read more about 42 Border Solutions That Are Not Title 42


42 Border Solutions That Are Not Title 42

Read more about Border Security Along the Southwest Border: Fact Sheet

Fact Sheet

Border Security Along the Southwest Border: Fact Sheet