U.S. stock markets fell sharply Thursday as Portugal’s Espirito Santo Financial Group (LS:BES) decided to delay a debt payment and sparked scary memories of the recent financial crises that wracked Europe.

The Dow Jones Industrial Average fell 1 percent, or more than 170 points, while the Nasdaq and S&P 500 fell 1.5 percent and 1 percent respectively.

MarketWatch.com reported that should the S&P losses hold throughout the day it would be the index’s worst performance in three months.

Shares across Europe fell sharply too.

Espirito Santo Financial Group, the largest shareholder in Banco Espirito Santo, halted trading in its securities on Thursday after the missed debt payment, citing an “ongoing material difficulties at its largest shareholder Espírito Santo International S.A.”