Joe Alton was sitting on his patio Thursday night in St. Paul when he and his girlfriend heard a strange sound.

It sounded “like a slow wave … like a weird little roar,” he said, adding that he heard snapping branches and what sounded like metal on metal.

“I had no idea what it was,” Alton said.

He quickly learned that a landslide had occurred on an embankment along the edge of a parking lot at a Grand Hill apartment building.

A few miles away Friday morning, another landslide closed part of Indian Mounds Regional Park in St. Paul.

About 25 feet of bluff gave way at the park overlooking the Mississippi River bluffs near Mounds Boulevard, said Brad Meyer, spokesman for the city Parks and Recreation Department.

The city closed that area of the park, but the rest of the park remained open.

Meanwhile, flooding closed several St. Paul parks, and Meyer said crews were assessing the danger at other parks.

“Right now, we don’t have any defined hazards at any open parks,” he said.

In Minneapolis, investigators were on the scene Friday of a landslide at the University of Minnesota Medical Center’s West Bank campus, where a section of rain-soaked Mississippi River bluff land collapsed onto West River Parkway on Thursday night.

No one was hurt in the 100-yard-wide landslide, and the hospital said patient care wasn’t affected.

Engineers examined the buildings closest to the mudslide and deemed them structurally sound, the hospital said.

“The hospital … is actually quite far removed from … the mudslide,” said Carolyn Wilson, medical center president. “The buildings that are closest to the banks of the Mississippi are non-patient care areas, and we do have geologists working with our structural engineers here. They’ve assured us and the city that … the buildings even close to the banks are on bedrock, and … they’re testing how deep that is, but they are assuring us that we can be here and care for patients safely.”

The hospital had liquid oxygen tanks near the mudslide site, and the fire department determined they were safe. A hospital spokeswoman said they wanted to assess the area underneath the tanks, which required relocating a piece of equipment and emptying the tanks of oxygen Friday. The hospital warned it would create a cloud visible to the public.

The University of Minnesota Medical Center’s East Bank campus will also be studied by engineers, the hospital said.

Part of Minnesota 13 in Mendota Heights remained closed Friday after mudslides covered about 40 feet of the road between Sylvandale Road and Wachtler Avenue.

Detours were posted, and the hope was that crews could clear the road of mud and debris and have it open by Saturday afternoon, said Mike Kowski, a MnDOT maintenance resource engineer.

“It’s a few feet deep, and there are lots of small trees and some downed (telephone) lines,” he said.