The Mexicans are already tunneling under it.
“Cross-border smuggling tunnel discovered in Otay Mesa; $29.6M worth of drugs seized”
https://www.sandiegouniontribune.com/news/public-safety/story/2020-03-31/cross-border-smuggling-tunnel-discovered-nearly-30m-worth-of-drugs-seized?utm_source=SDUT+News+Alerts&utm_campaign=ca5c100706-EMAIL_CAMPAIGN_2020_03_31_05_26&utm_medium=email&utm_term=0_d8e1c88c4e-ca5c100706-85944653
tunnel detecting will become a necessity.