(CNN)For nearly two weeks, Shirell Powell stood vigil over her brother's bedside in a New York hospital, believing there was nothing more doctors could do to save him.
Case of mistaken identity leads sister to withdraw life support for a man who wasn't her brother, lawsuit claims
She was told he was brain-dead -- the result of a narcotics overdose -- so in late July 2018, a grieving Powell gave her permission to take him off life support and her brother was pronounced dead.
A couple of weeks later, Powell was notified that the man she was about to lay to rest was someone with a similar name, Freddy Clarence Williams. Her brother, 40-year-old Frederick Williams, was very much alive.
Powell is suing St. Barnabas Hospital for negligence and is seeking monetary relief. She says she "suffered severe emotional harm and injuries" as a result of the hospital mistakenly identifying the unconscious man as her brother, according to court documents.
Steven Clark, a spokesman for the Bronx, New York, hospital, said it doesn't comment on pending litigation, but that the hospital doesn't "believe the claim has any merit."
In mid-July 2018, an unconscious man named Freddy Clarence Williams was admitted to St. Barnabas Hospital and identified by the Social Security card he was carrying, Powell's lawsuit says.
Powell's brother, Frederick Williams, had previously been a patient at the hospital, and Powell was among those listed in his patient profile as an emergency contact.
Powell says in her lawsuit that she was contacted by the hospital and told by a doctor that "he did not think that Frederick Williams would 'make it'" and that he would be transferred to the hospital's hospice inpatient unit.
A couple of weeks later, Powell made the decision to take her brother off life support and began making preparations for his burial. When an autopsy was conducted, a staff member at the New York Medical Examiner's Office made it apparent to Powell that the man she grieved over was not her brother, but a man who shared a common name and a similar appearance.
Powell's attorney, Alexander Dudelson, said the man she believed to be her brother was swollen and was wrapped in a neck brace and tubes at the hospital, altering his appearance. Both Powell and several members of her family believed the man was their relative, he said.
"I've seen pictures of the gentleman in the bed. He had a neck brace and tubes. Everything was very similar. When a hospital tells you this is your brother and there's a resemblance, you're inclined to believe it."
Dudelson said such resemblance does not absolve the hospital of wrongdoing, noting it neglected to check details that would have proved the two men were different people.
"The dates of birth were off and the Social Security was off. The names were different," Dudelson said.
Powell's brother, Frederick Williams, is alive and is being held at a correctional facility on Rikers Island, according to court records, which show he was arrested on a misdemeanor assault charge and is awaiting a court date. CNN was unable to determine if Williams has a lawyer or if he has entered a plea.
Powell did not hear from her brother until after the mix-up was discovered.
"I don't have any siblings, but I sometimes go a couple weeks without speaking to a best friend. A two-week span may not have been a big deal, especially when someone is incarcerated," Dudelson said.
The man who died on July 29, 2018, remains a mystery. No family members or close friends have come forward.
Dudelson said he sent a letter to the hospital before Powell's suit was filed, requesting an investigation. In response, he received a letter from the hospital's attorneys stating that because his client was not related to Freddy Clarence Williams, they could not "provide ... any information regarding this patient under the present circumstances."
"Further, the facts you allege in your letter, even if they were accurate, would not constitute a cognizable cause of action. Please understand, if you commence a suit, we will seek all available relief against you and your client for frivolous litigation," the letter states.
Powell has "suffered emotionally" and is in counseling, Dudelson said. "I hope this never happens again. The whole thing is sickening."