Three people are dead in North Dakota, and tens of thousands are without power in northern Minnesota and northwestern Wisconsin after powerful winds swept across the upper Midwest Friday and overnight Saturday.

Powerful winds — including a tornado — that swept across parts of the upper Midwest left three people dead and a regional airport heavily damaged, while nearly 150 million Americans were under a heat advisory or warning as the weekend warms up much of the U.

At least three people are dead in rural North Dakota after tornadoes left damage across eastern areas of the state, the Cass County Sheriff’s Office said in a release Saturday.