Hillary Clinton went for Donald Trump’s proverbial Achilles heel—his record with bankruptcy—as a warning about he would handle the U.S. economy.

Clinton appeared before union members in Detroit on Monday and got personal with the presumptive Republican nominee for his failed business ventures, particularly his casino holdings in Atlantic City.

The Democratic candidate was quoted by Politico saying: “Trump economics is a recipe for lower wages, fewer jobs, more debt. He could bankrupt America like he’s bankrupted his companies. I mean, ask yourself, how can anybody lose money running a casino? Really.”

Trump has filed a total of four business bankruptcies in the last 30 years, and all of them were about his failed casinos in New Jersey.