RAPID CITY, SD (KELO) — Fifty years later, it’s hard to wrap our minds around the devastation caused by one of the worst natural disasters in U.S. history.

REPORTER STEVE HEMMINGSEN: “June 9th 1972, the skies opened above the Black Hills, sending water rushing through the streams and canyons.”

Gripping images of the damage in Rapid City and first-hand accounts of those swept-away by the ferocious current bring back a time, 50-years ago, that forever changed a city and those who survived.

“It was really like you were in an ocean. I’d be thrown and towed under and thrown. It was like the roar of a train, you can’t imagine. It was just awful,” flood survivor Millie Dieter said in 1982.

Heartbroken families took a grim walk through makeshift morgues to identify loved ones lost in the flood. The nation grieved with South Dakota. First Lady Pat Nixon was among those who attended a memorial service in Rapid City. Meanwhile, volunteers and the military mobilized for cleanup.

REPORTER: “National guardsmen who would normally be bivouacked spent their two-week training period on the most massive cleanup project they would ever see.”

The cleanup would last for months. The rebuilding, for years. The city placed zoning restrictions along Rapid Creek to minimize the damage in case the unthinkable would ever happen again.

238 people died in the flood. Damage totaled $160-million dollars in 1972, which would be almost one-billion in today’s dollars.