SULPHUR, Okla. (AP) — Small towns in Oklahoma began a long cleanup Monday after tornadoes flattened homes and buildings and killed four people, including an infant, widening a destructive outbreak of severe weather across the middle of the U.S.

Punishing storms that began late Saturday in Oklahoma injured at least 100 people, damaged a rural hospital, washed out roads and knocked out power to more than 40,000 customers at one point, state officials said. Tornadoes on Friday in Iowa and Nebraska also caused wide destruction and were blamed for one death.

The destruction was extensive in Sulphur, a town of about 5,000 people south of Oklahoma City, where a tornado crumpled many downtown buildings, tossed cars and buses and sheared the roofs off houses across a 15-block radius.

“You just can’t believe the destruction,” Oklahoma Gov. Kevin Stitt said during a visit to the hard-hit town. “It seems like every business downtown has been destroyed.”