The cause of actress Betty White’s death on New Year’s Eve, at age 99, was a stroke she had suffered nearly a week earlier, a copy of the performer’s death certificate posted online by on Monday showed.

The partially redacted certificate stated White’s cause of death as a “cerebrovascular accident,” a medical term for a stroke or the loss of blood flow to the brain caused by a clot or ruptured blood vessels, resulting in brain tissue damage.

Jeff Witjas, White’s longtime agent, said in a statement: “Betty passed in her sleep peacefully without pain. To me, this is the most important thing and brings me comfort as her dear friend. Anything else is private to Betty.”

White, who remained a pop culture phenomenon well into her 90s, long after Emmy-winning roles on television sitcoms “The Golden Girls” and “The Mary Tyler Moore Show,” died on Dec. 31 less than three weeks shy of her 100th birthday.

She married her third and final husband, “Password” game show host Allen Ludden, in 1963.