As shown in this aerial photo, parts of historic Ellicott City and, across the river, Oella, were under water for days when Tropical Storm Agnes swept through the region, dumping 10 to 14 inches of rain on already saturated areas. (File photo/1972 / June 20, 2012)

At about 2 a.m. on June 22, 1972, Kevin Ford, 17, answered a knock at the door of his family's row home on the banks of the Patapsco River in Oella — the same home his grandparents first moved to in 1912 — to find a couple of Baltimore County police officers standing in the wind and the rain.

They were there with a warning: Flood gates upstream at the Liberty Reservoir were about to be opened to alleviate the pressure caused by all the rain Tropical Storm Agnes had been dumping on the region, and Ford's riverside home wasn't safe.

The teenager's parents were out of town. So he and one of his aunts quickly gathered a few belongings and headed, half-asleep, into the storm to the home of another of Ford's aunts on Old Frederick Road.

The entire experience was jolting, Ford recalls.

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"You're 17. You don't know what's going on. It's raining really hard and you can't see. And they're telling you to get out, because they don't know what's going to happen," said Ford, now 57 and living in the same home.

The next morning, he wound his way back through Oella's hills — past the W.J. Dickey & Sons Textile Mill, just upstream from his home — to find the raging storm waters had radically changed the landscape.

The river was wider than he'd ever seen it, and had torn through and covered one of its banks where Ford's family had long strung clothes lines in front of their home.

"The water got high enough that it washed the bank away and the back of the garages fell out, and the garages were right here in front of the house," Ford said.

Such was the immediate and sudden presence in the old mill town of Tropical Storm Agnes, an episode of massive destruction that would become one of the worst natural disasters ever to hit Maryland and one of the costliest storms in the nation's history, with billions of dollars in estimated damages.

Locally, the storm, which had been a hurricane in the south, submerged the lower end of nearby historic Ellicott City in flood waters and wreaked havoc in other low-lying areas of the county and region, destroying homes and businesses and washing out bridges and roadways.

The storm dropped an estimated 10 to 14 inches of rain on Maryland, Virginia and Pennsylvania and caused massive flooding from North Carolina to New York. It killed seven people along the Patapsco River, a total of 19 in Maryland and 122 along the East Coast, according to reports from local newspapers and the National Weather Service.

In the Baltimore area, Agnes caused thousands to be evacuated from the Jones Falls Valley and other low-lying areas, including Lansdowne.

Electricity and phone service were knocked out for thousands. Millions of gallons of sewage spilled into waterways from disturbed pipes and plants in Savage and elsewhere. The state issued warnings for people to boil their water, and President Richard Nixon declared the state a disaster area, according to local reports.

Today, 40 years later, the storm is remembered for its power and scope, and remains a key benchmark for local disasters. While the legacies of other great floods in the area, like those in 1868, 1923 and 1952, have largely faded, those who lived through Agnes remember its wrath.

"The flood waters did such devastation in that area where the bridge into Ellicott City was, it was just amazing," said Charles Wagandt, the great-grandson of William J. Dickey, who purchased Oella at auction in 1887 and started the mill.

Memories remain

Wagandt had purchased another mill and mill town, Dickeyville, on the Gwynns Falls near Woodlawn, just 36 hours before Agnes wiped out a bridge to the small town, leaving it completely isolated.

In 1973, Wagandt made another purchase, this time of a large portion of Oella, much of it damaged by Agnes the year prior.

"I thought it'd be an interesting challenge," he said, of rebuilding the damaged, historic town.

Throughout the county, those with distinct memories of the storm recall how it impacted their lives.