Many of the nation’s most at-risk housing markets for potential downturns were heavily concentrated in California, Illinois and the New York City area, according to a new report from Attom. The report also found that some parts of Florida were also in danger.

Metropolitan areas around New York City and Chicago, as well as broad swaths of California, had 23 of the 50 U.S. counties considered most vulnerable, including Cook, Kane, Kendall, McHenry and Will counties in Illinois. Counties that covered Brooklyn and Staten Island, and the New York City suburbs of Essex and Passaic were also considered highly in danger.

California had 14 counties that could be in danger of a housing downturn, including the areas around Chico, Oakland, Sacramento, Modesto, Redding, Riverside and San Bernadino, to name a few.

Those areas less vulnerable to a downturn were scattered across different regions of the Northeast, Midwest and South. The analysis is based on fourth-quarter housing trends that include affordability gaps, underwater mortgages, foreclosures and unemployment.

Attom analyzed 566 U.S. counties in the fourth quarter and found that 51 were identified as least vulnerable to housing market issues due to a tie in rankings. Among them were 23 counties in the South, 13 counties each in the Midwest and the Northeast and only two counties in the West.

One of the nation’s least risky states was Wisconsin, which had three counties topping the fourth quarter’s list. They included Winnebago County, Outagamie County and Brown County. Other states deemed least likely to suffer a housing decline include Virginia, Tennessee and Pennsylvania.