Prince George’s County government officials have issued a mandatory evacuation for homes in a Fort Washington subdivision where a slope failure over the weekend destabilized homes, collapsed a road and triggered a water main break. (Arelis R. Hernandez/The Washington Post)

Worried residents of an upscale waterfront community in Prince George’s County peppered government officials with questions Tuesday night about a landslide that has devastated their neighborhood. But answers — reassuring or otherwise — were hard to come by.

Officials told homeowners from the Piscataway Hills development that it is too early to say what caused the “slope failure” that ruptured water and sewer lines and sent trees tumbling and earth sliding in their neighborhood over the weekend. It is too early to know when the 28 custom-built homes will again be safe to inhabit, and too early to know whether insurance will pay for some of the damage.

“I know this is a hard time for you,” Nick Majett, acting chief administrative officer for Prince George’s, told about 30 residents gathered at the Harmony Hall Regional Center, which the county government is using as its headquarters for dealing with the situation. “I can’t imagine how it feels to be forced out of your home by a catastrophe.”

Frustrated homeowners urged officials to move quickly to stabilize the hill on which many of them have built their dream homes. The neighborhood hugs a hillside that descends to Piscataway Creek, a tributary of the Potomac in a bucolic section of Prince George’s that borders National Park Service land.

Falling trees are a habitual hazard in the enclave, about seven miles south of the Capital Beltway, residents said. And for years, cracks have opened along Piscataway Drive and work crews have come to fill them.

Over three days, starting Friday, about 1,500 feet of hillside slid about three feet toward a section of the street, officials said. Trees as tall as 200 feet crashed down, taking power lines with them.

County workers patched the road, but the water and sewer lines broke. Three times, Washington Suburban Sanitary Commission crews repaired the pipes, which were installed in 2009. But both lines ruptured again Sunday because of the pressure from the moving soil.

A quarter-mile stretch of Piscataway Drive now appears to be dislodging and slipping down a steep slope toward a vacant but enormous home known by neighbors as “the Millers’ place.” The owners died some time ago, residents said.

“Is this being done with county funds or who is going to pay for this?” James Roy, a contractor who moved to the community with his wife six months ago, asked, referring to road repairs, damage to homes and potentially long hotel stays for displaced residents. He said a call to his insurer has him unnerved.

On Tuesday, the unstable land slid 2½ inches, authorities said. County officials tried to convince residents of about five or six homes who had refused to evacuate that it was not safe for them to stay.

A total of 28 houses were included in the evacuation order issued Monday as a result of the landslide. Six of the homes — including the vacant one — were damaged by the slope failure. The 22 others were without water and sewer service and electricity, and were not safely reachable because of the collapse in the roadway.

“No one imagined it would slip this much,” resident Debbie Kutzleb said.

Geotechnical engineers said the soil is dense Marlboro clay, which is well known for triggering landslides in the Washington area. Marlboro clay deposits of varying thickness and composition are pervasive in southern Prince George’s County, according to the Maryland Geological Survey.

By Sunday evening, Prince George’s officials had closed part of Piscataway Drive. Kutzleb and her neighbors parked their vehicles outside the closed zone, then walked to them Monday morning so they could get wherever they needed to go. Kutzleb took a trip to the post office to forward her mail, as Postal Service trucks wouldn’t have access to the neighborhood. When she returned, she found the road lined with county and emergency vehicles and an evacuation notice affixed to her door.

“I took a picture of the notice and sent it to my husband,” who is working in Australia, Kutzleb said. “I grabbed my cat, Alley, made arrangements for her, got a clothes basket full of clothes and my vitamins.”

Residents say they know that living deep in a wooded wetland can complicate some ordinary domestic tasks. But they say that’s the price they pay for living among wildlife and near water.

They are used to helping one another. When trees fall, neighbors work together to cut them up. When snow maroons those at the bottom of the hill, neighbors check on one another. And when homeowners are stranded, others step up to provide hospitality.

A neighbor offered to drive Sue Howland down the hill to her home beyond the barricade to retrieve her cats and her husband, Ken Archer, an amputee. Howland grabbed the licenses for all of her 20 pets and took about half of the cats with her to the Red Roof Inn in Alexandria.

Howland said she moved from Northern Virginia to her brick-faced house about a decade ago. The house stands on stilts and has a large patio that overlooks the creek. “It’s wonderful. I love living here,” she said.

Officials said heavy rains last week may have triggered the slide.

“I think these things are so fluid, it will take a long time for this situation to stabilize,” Kutzleb said. “The [county officials] had to do what they had to do.”

County agencies said Tuesday that they were trying to contact every affected family. “We want to make sure we can get in touch with every single resident and make sure they have the full range of resources available to them,” said Scott Peterson, a spokesman for County Executive Rushern L. Baker III (D).

Dana Hedgpeth contributed to this report.