Gibb died Sunday after emergency surgery for an intestinal blockage. He was 53. He had been admitted to Mount Sinai Medical Center four days earlier, and had suffered cardiac arrest before the operation.
His death was a shock to his bandmate brothers, Robin and Barry Gibb.
"We're both devastated. We've actually been in shock for the last few days since Maurice was taken ill, and so this has all gone too fast for us," Robin Gibb told the British Broadcasting Corp. on Sunday. "It's like a nightmare that you wake up to every day. That's all we can say. It's just devastating. It's going to take a long time even just for it to sink in."
The surviving Gibbs claimed that mistakes were made by the hospital in the death of "one of the world's greatest recording artists." They questioned whether it was necessary to operate on Maurice when he was in a state of cardiac arrest.
"We believe mistakes were made and time was wasted," Robin Gibb told the BBC.
Hospital spokeswoman Kathleen Dorkowski said she could not comment on the allegations because of patient privacy laws.
Fans sent flowers to the hospital and the brothers' homes in England, said Pete Bassett, a spokesman for Barry Gibb.
"He was a truly talented artist and a wonderful man full of wit and passion for life," Bee Gees manager Allen Kovac said in a statement.
The Bee Gees, short for the Brothers Gibb - twins Maurice and Robin, and older brother Barry - were known for their tight, high harmonies and original sound. Their younger brother, Andy, who had a successful solo career, died in 1988 at age 30 from a heart ailment.
The brothers had nine No. 1 songs, wrote dozens of hits for other artists, and sold more than 110 million records - placing them fifth in pop history behind Elvis Presley, the Beatles, Michael Jackson and Paul McCartney.
The group's contributions to the "Saturday Night Fever" album in 1977 made it the best selling movie soundtrack ever, with more than 40 million copies sold.
The Bee Gees became members of the Rock and Roll Hall of Fame and won seven Grammy Awards.
Maurice Gibb, a recovering alcoholic, once lamented how some perceived the band, best known for hits like "Stayin' Alive," simply as a disco phenomenon.
"People accuse us of being nothing more than a disco band now," Gibb said in a 1978 interview with TG Magazine. "But they don't know what they're talking about. If you listen to our records, you'll find that there's dance music. But there are also ballads like 'More Than A Woman.' And there are some very beautiful, undanceable songs, too."
Originally from England, the brothers gained fame as a teen pop group in Australia, then returned to England in the 1960s. Their first four albums contained hits such as "1941 New York Mining Disaster," and their first U.S. No. 1 song, 1971's "How Can You Mend A Broken Heart." They have lived in South Florida since the late '70s.
Their 1978 album "Spirits Having Flown" sold 20 million copies.
In the 1990s, the Bee Gees released three studio albums and went on a world tour. The live tour album, "One Night Only," sold more than 1 million albums in the United States.
Gibb's first wife was British singer Lulu. He and his second wife, Yvonne, were married for more than 20 years and had two children.
By Adrian Sainz