Large parts of the U.S. Central Plains were underwater on Saturday after a late-winter “bomb cyclone” storm triggered flooding along rivers, causing two deaths, drowning homes and swallowing roadways.

Nebraska has had two flood-related fatalities this week: one person died at home after failing to evacuate, although the exact cause of death was unclear, authorities said, and the other was swept away while trying to tow a trapped car with his tractor.Residents in towns along the waterways worked to fill sandbags, in hopes of keeping floodwaters at bay.

The flooding came in the wake of what meteorologists call a “bomb cyclone,” a winter hurricane that forms when the barometric pressure drops 24 millibars in 24 hours.

The storm blew from the western Rockies to the Central Plains last week.