BALTIMORE — Nancy Waldhaus has lived in her South Baltimore home since 1994. But what lies roughly 30 feet beneath it — a network of caverns left behind by 19th-century mining operations — may now be threatening the house she has called home for more than three decades.
"You're just kind of like at a level of vigilance that's tiring," Waldhaus said.
In April 2024, after a large rainstorm, Waldhaus noticed a tree on the city-owned lot next to her house had suddenly lost several feet of height. She filed a report with 3-1-1. Shortly after, cracks began appearing in and around her home.
WATCH: South Baltimore home may sit above 19th-century mining caverns
"This is where I first noticed I could put my hands under the baseboard. And it maybe stopped about here. But now it's continued to shift all the way to the end of the bathroom," Waldhaus said.
The signs pointed to land movement beneath her property.
"I got very worried that I could wake up in a hole," Waldhaus said.
Waldhaus hired a structural engineering company to assess the situation. When cracks reached a 2-millimeter threshold within just a few days, the engineer recommended going further.
"And he said you really need to do borings and see what's at the side of your house," Waldhaus said.
To conduct those borings, she needed permission from the city — which, months after her initial report, had taken no action.
"The city was trying to figure out who in the, you know, city departments was really responsible for this lot," Waldhaus said.
A history buried underground
Through conversations with neighbors, Waldhaus learned what had long been hidden beneath that vacant lot and possibly her home. As far back as the 1850s, South Baltimore residents had dug into the ground to extract natural resources — primarily sand and clay used to manufacture glass, bricks, and sewer pipes, some of which remain in use around the city today. The caverns left behind were eventually filled in and largely forgotten.
William Vincett, a coastal plains geologist with the Maryland Geological Survey, reviewed a city report that one of Waldhaus's neighbors had discovered.
"The changes in the South Baltimore area is a story about increasing population, it's a story about extracting, it's a story about natural resources, it's a story about the people interacting with the water," Vincett said.
The report was published in October of 1951, when the basements of five houses on East Clement Street suddenly collapsed. A comprehensive city study at the time found an extensive network of caverns from 19th-century mining operations about 30 feet below the surface. The city condemned the properties, demolished the houses, and paved over the area. The vacant lot that was created sits directly next to Waldhaus's home today.
"It appears that there was some in filling of material to fill the voids or the previously mined areas, they filled it in with sand and clay, um, other materials," Vincett said.
The 1951 report suggested the area could be stabilized, stating: "By establishing a permanent record of conditions found there, and now known to exist in the area. With this advance information at hand, it is quite possible that a similar disaster can be checked, with a minimum of property damage and without loss of life." Who should act on that finding, and how, remains unanswered.
Cracks keep growing, answers remain elusive
Waldhaus says the movement around her home has continued and the city has only done relatively surface searches.
"There was an initial survey that was done from the surface that went down 6 feet, um, but we knew the tunnels were deeper and the caverns were deeper," Waldhaus said.
A Department of Public Works engineer told Waldhaus the city was working to "determine the appropriate remediation strategies and associated costs," and that "further communication moving forward will be coordinated through the law department." However she has yet to hear back from the city about any decision.
"There's been further deterioration. I repair my house when I see something. And I was stuck uh because I need the assessment completed," Waldhaus said.
We reached out to several involved city departments but so far none have agree to speak with us.
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