While President Trump was building more than 482 km of his border wall, between 2017 and 2021, Customs and Border Protection discovered almost a new tunnel per month; within these tunnels, the longest ever discovered was found, which was about 731 meters long.
The construction of the border wall, which cost $1.4 billion, has not served its intended purpose, as it has not prevented smugglers from building 40 tunnels under the border or using ladders or power tools to cross it.
It is unknown how many migrants or drug traffickers managed to cross these tunnels. What is known is that the longest one, discovered in 2016, was equipped with rails, ventilation systems, lights, and even a sophisticated elevator, according to a summary of a 2016 press release from the U.S. Attorney's Office for the Southern District of California.
This is how former President Trump described the wall in response to warnings about the potential for tunnels. According to the Science and Technology Directorate of the U.S. Department of Homeland Security, it has been concluded so far that no current technology is adequate for detecting tunnels under the border.
Federal authorities have detected more than 75 cross-border smuggling tunnels since 2011, most of them in California and Arizona. It is important to note that the border wall is breached nearly 11 times a day; the number of breaches reached 4,101 in 2022, the highest number recorded during that period, according to a summary of a statement from the U.S. Attorney's Office for the Southern District of California.
Source: Cato, Justice.gov, El Mundo