Lord Glenarthur, the chairman of King Edward VII's Hospital, wrote the chairman of the radio station's owner to urge him not to let such a thing happen again.
The consequence of the prank for "was the humiliation of two dedicated and caring nurses who were simply doing their job tending to their patients," he wrote.
"The longer term consequence has been reported around the world and is, frankly, tragic beyond words."
Jacintha Saldanha, 46, was found dead early Friday at nurses' housing provided by London's King Edward VII hospital, where Prince William's wife, the former Kate Middleton, was being treated for acute morning sickness this week.
Police released a grainy photo of Saldanha on Saturday. A native of India, she had lived in Bristol in southwestern England with her family for the past nine years, Scotland Yard confirmed.
Police said her death is being treated as "unexplained," though they said they didn't find anything suspicious. A coroner will make a determination on the cause next week.
Police have made no connection between her death and the prank call, but people from London to Sydney have been making the assumption that she died because of stress from the call.
Flowers were left outside the hospital's nurses' building. Attached to the red, white and blue flowers, a note read: "Dear Jacintha, our thoughts are with you and your family. From all your fellow nurses, we bless your soul. God bless."
A man identified as Saldanha's driving instructor Jeff Sellick, told Sky News he was in "complete shock" at her death, saying "it's just such a shame, she was such a nice person."
In a statement, Saldanha's family said they were "deeply saddened" by the death and asked for privacy.
Saldanha had worked for four years at the hospital. She took the hoax call Tuesday by the two DJs from 2DayFM, and transferred the call to the nurse caring for the duchess. During the call, a woman using the often-mimicked voice of Britain's monarch asked about the duchess' health. She was told by the second nurse who took the call from Saldanha that the duchess, the former Kate Middleton, "hasn't had any retching with me and she's been sleeping on and off."
The recorded conversation sparked international headlines, and the DJs, Mel Greig and Michael Christian, soon apologized for the prank. They have said they will not return to the station until further notice, though the chief executive of the station's parent company has said he stands behind them.
The Australian Communications and Media Authority, which regulates radio broadcasting, says it has received complaints about the prank and is discussing the matter with the Sydney-based station, though it has not yet begun an investigation.
The station has a history of controversy, including a series of "Heartless Hotline" shows in which disadvantage people were offered a prize that could be taken away from them by listeners.
St. James's Palace, the office of the duchess and her husband Prince William, expressed sadness at Saldanha's death, but insisted that it had not complained about the hoax. King Edward VII's Hospital said it did not reprimand Saldanha, nor had plans to discipline her.
Officials from St. James's Palace have said the duchess is not yet 12 weeks pregnant. The child would be the first for her and William.