BALTIMORE — Nancy Waldhaus has been a resident of her South Baltimore home since 1994. However, an unsettling discovery about 30 feet beneath her property—a network of caverns formed by mining activities from the 19th century—could pose a serious threat to the home she has cherished for over three decades.
“You find yourself in a constant state of vigilance, which can be quite exhausting,” Waldhaus remarked.
In April 2024, following a heavy rainfall, Waldhaus observed that a tree on the city-owned lot adjacent to her property had inexplicably shrunk several feet in height. This prompted her to file a report through the city’s 3-1-1 service. Shortly thereafter, cracks began to emerge both inside and around her home.
WATCH: South Baltimore home may sit above 19th-century mining caverns
South Baltimore home may sit above 19th-century mining caverns
“I first noticed that I could slide my hands underneath the baseboard, which initially stopped here. But now, it has shifted all the way to the length of the bathroom,” Waldhaus explained.
The indications pointed towards ground movement occurring beneath her property.
“I became very anxious at the thought that I might wake up in a hole,” Waldhaus confessed.
In response to her concerns, she enlisted a structural engineering firm to evaluate the situation. When cracks rapidly reached a 2-millimeter threshold in just days, the engineer advised further investigation.
“He indicated that we needed to perform borings to assess what was beneath the side of my house,” Waldhaus said.
However, acquiring the necessary permission from the city for those borings proved challenging, and months after her initial report, no action had been taken.
“The city was deliberating on which department was responsible for this lot,” Waldhaus noted.
A history buried underground
As she spoke with neighbors, Waldhaus uncovered the long-forgotten history buried beneath the vacant lot and possibly her own property. As far back as the 1850s, South Baltimore residents engaged in mining activities to extract natural resources—primarily sand and clay, which were used in the production of glass, bricks, and sewer pipes, some of which are still in operation throughout the city today. The caverns left behind were eventually filled in and largely overlooked.
William Vincett, a coastal plains geologist with the Maryland Geological Survey, reviewed a city report that one of Waldhaus’s neighbors had discovered.
“The evolution of the South Baltimore area reveals a narrative about population growth, resource extraction, and community interactions with water,” Vincett stated.
The report, published in October 1951, followed the sudden collapse of five homes on East Clement Street. A comprehensive city study at that time exposed a vast network of mining caverns located approximately 30 feet beneath the surface. As a result, the city condemned the properties, demolished the structures, and paved the area. The vacant lot that emerged now lies directly adjacent to Waldhaus’s home.
“It seems that some material was used to fill the voids or the mined areas, primarily sand and clay among other materials,” Vincett explained.
The 1951 report proposed that the area could be stabilized, suggesting: “By keeping a permanent record of the conditions found there, it is likely that a similar disaster could be mitigated, minimizing property damage and preventing loss of life.” However, questions remain about who should address these findings and how to proceed.
Cracks keep growing, answers remain elusive
Waldhaus reports that ground movement around her home has persisted, while the city has only performed relatively superficial investigations.
“An initial survey was conducted from the surface, but it only extended down 6 feet, and we know that the tunnels and caverns are much deeper,” Waldhaus stated.
An engineer from the Department of Public Works informed Waldhaus that the city is currently working on “identifying appropriate remediation strategies and their associated costs,” with further communication to be coordinated through the law department. Yet, she has not received any updates from the city regarding a decision.
“There has been further deterioration. I attempt to make repairs whenever I notice an issue, but I’ve been hindered by the need for a complete assessment,” Waldhaus explained.
We reached out to various city departments involved, but thus far, none have agreed to provide a statement.
This story was reported on-air by a journalist and has been adapted for this platform with assistance from AI. Our editorial team rigorously verifies all reporting across platforms to ensure fairness and accuracy.
