Updated 12:07 p.m.

Fire investigators are at the scene of the fire trying to determine a cause. The investigation could take as long as five days because of the extent of the damage, fire department spokeswoman Tiffany Bradbury said.

Damage estimates are at least $3 million to $4 million.

In addition to the dialysis center, the building also had two penthouse apartments and another medical office.

Posted 1:55 a.m.

A building fire in South Roanoke Wednesday evening shuttered a dialysis center and left 72 patients to find alternative treatment locations.

Roanoke City Fire-EMS crews contained a four-alarm fire in the Cambridge Building, which houses the Fresenius Medical Care Crystal Spring Dialysis center, in the 400 block of McClanahan Street in South Roanoke Wednesday night, Deputy Chief Ralph Tartaglia said.

Roanoke City Fire-EMS spokeswoman Tffany Bradbury said a call came in around 10:20 p.m., and Tartaglia said crews arrived and declared a working fire at the building by 10:26 p.m. Roanoke pooled about 80 percent of its fire resources to respond to the fire, and crews from Salem and Vinton were called on to fill in as backup at Roanoke city fire stations for the occupied crews.

No one was in the building at the time of the fire, and there were no injuries. Crews were able to save about 60 percent of the building, Tartaglia said. Residents of a nearby apartment building were not affected by the blaze.

Bob Hudson, the regional director of operations for Fresenius Medical Care, said the clinic's biggest concern at the moment is to make sure patients are treated. He said the clinic's 72 patients will have to seek treatment at nearby locations, including North Roanoke Dialysis in Roanoke and Roanoke Salem Dialysis in Salem.

Patients with any questions or concerns can call (540) 725-1796.