CHARLESTON, W.Va. — The FBI is involved in an investigation of suspicious deaths at a Veterans Affairs hospital in West Virginia, according to a lawyer for the estate of a Vietnam veteran who died at the facility.

Attorney Tony O’Dell said Thursday that his client and others have indicated the bureau is involved in investigating the Louis A. Johnson VA Medical Center in Clarksburg.

O’Dell represents the estate of Army Sgt. Felix Kirk McDermott. He’s filed notice of a pending lawsuit that says the 82-year-old was wrongly injected with a fatal dose of insulin at the hospital in April 2018. The death was ruled a homicide.

As many as 11 suspicious deaths have occurred at the hospital, U.S. Sen Joe Manchin has said. The West Virginia Democrat said Thursday that he spoke with U.S. Attorney General William Barr about the deaths and has been assured that the Department of Justice will provide resources during the investigation.

The FBI referred questions to the local U.S. attorney’s office, which has declined to confirm or deny an investigation. The VA’s inspector general has confirmed he is investigating “potential wrongdoing resulting in patient deaths” at the hospital.

Manchin says the VA inspector general told his office about the opening of a medical and criminal investigation of the hospital in July 2018, after at least nine patients were diagnosed with unexplained low blood sugar. He said he told Barr in a letter that he has “grave concerns over the pace of the investigation.”

A lawyer for the family of another veteran told The Associated Press on Thursday that George Nelson Shaw Sr., a retired member of the Air Force, also died at the hospital in April 2018 from a wrongful insulin injection that was later classified as a homicide.

Attorney David Glover said Shaw had been in the Air Force for 28 years and later worked at the Clarksburg VA hospital before his death at 81 years old.

“This is a military family,” Glover said. “They put their trust in the VA and they feel total betrayal.”