Prototypes for US President Donald Trump's proposed border wall with Mexico have been completed and will be subjected to punishment to test their mettle - by workers wielding sledgehammers, torches, pickaxes and battery-operated tools.
The testing, lasting up to two months, could lead to officials concluding that elements of several designs should be merged to create effective walls, said Ronald Vitiello, US Customs and Border Protection's acting deputy commissioner.
Results of the testing will dictate future wall construction, which has not yet been funded by Congress.
The testing will not start for at least a month because some concrete in the wall prototypes still needs to dry.
Vitiello told reporters that workers during the 30-60-day testing period will try to answer basic questions: "Can it be climbed? Can it be dug under? Can it withstand cutting tools?"
The prototypes were built along the US border with Tijuana, Mexico.
Trump has asked Congress for 1.6 billion US dollars (£1.2 million) for the first instalment of his wall. It would replace 14 miles in San Diego and build 60 miles in Texas' Rio Grande Valley, the busiest corridor for illegal crossings.