SAN DIEGO (AP) — A jackhammer reduced prototypes of President Donald Trump’s prized border wall into piles of rubble Wednesday, a quick ending to an experiment that turned into a spectacle at times.

The four concrete and four steel panels, spaced closely together steps from an existing barrier separating San Diego and Tijuana, Mexico, instantly became powerful symbols associated with the president and one of his top priorities when they went up 16 months ago.

For Trump’s allies, the towering models were a show of his commitment to border security and making good on a core campaign promise. For detractors, they were monuments to wasted taxpayer dollars and a misguided display of aggression toward Mexico and immigrants seeking a new home in the United States.

Within about two hours, a hydraulic jackhammer on an excavator leveled seven prototypes. Concrete slabs crashed in small clouds of dust, steel panels were knocked over, and an owl flew out of a steel tube atop one panel just before it thundered down. The last prototype standing took a little more time to destroy.