Rivera's plane plunged from 28,000 feet

Mexican-American singer Jenni Rivera died Sunday, December 9, when the small plane she was traveling in crashed in the mountains of northern Mexico, her brother told CNN. Rivera, 43, was known to fans as "La Diva de la Banda," or the Diva of Banda Music, establishing herself as a musical powerhouse with her Spanish-language performances of regional Mexican corridos, or ballads. Recently, she had been working to crack the English-language U.S. market. Federal police are on hand at a base near the plane crash site Sunday in Iturbide, Mexico. "The aircraft was destroyed, totally fragmented," an aviation official told CNN affiliate Televisa. Six others were killed, including the singer's publicist, attorney and makeup artists, her brother, Gustavo Rivera, told CNN en Espanol. A helicopter flies over the crash site Sunday as investigators search the area. The cause of the crash was not immediately clear. Civil protection personnel and soldiers inspect the perimeter of the crash site Sunday. The plane took off early Sunday from Monterrey, Mexico, and shortly lost contact with air traffic controllers. Workers search around the accident scene in Mexico's Sierra Madre Oriental mountain range. Security members work at the site of the plane wreckage. Forensic technicians arrive at a base set up by federal police near the plane crash site. Singer's plane was flying at 28,000 feet when it began to plummet, official says It could have plunged at more than 600 mph, the transportation secretary says Determining what caused the crash in northern Mexico could take up to a year Some of Rivera's family members believe she could be alive Monterrey, Mexico (CNN) -- Even as Mexico's top transportation official said the plane carrying Jenni Rivera spiraled to the ground in a tailspin that may have surpassed 600 mph, some of the singer's family members were holding out hope on Wednesday. The plane was flying at 28,000 feet when it began to plummet, Gerardo Ruiz, Mexico's transportation secretary, told reporters. It crashed in a mountainous area 9,000 feet above sea level, he said. Determining what caused Sunday's crash could take up to a year, officials said. Authorities were still working Wednesday to identify remains found at the crash site in a remote area of northern Mexico. Rivera and six others were thought to be on board the plane, which lost contact with air traffic controllers soon after takeoff. In California, the Mexican-American singer's mother said her grandchildren still think Rivera is alive. "They continue thinking that their mother is OK, that God could perform a miracle," said Rosa Saavedra, noting she was trying to stay strong to support them. Remembering singer Jenni Rivera The legacy of Jenni Rivera Rivera's plane's linked to ex-con Pedro Rivera Jr., one of the singer's brothers, said the family was waiting to read a document detailing her wishes that she had left with a sister about a month ago. "She cannot read it yet, she can't say anything to us yet, until we are 100% sure that Jenni is no longer with us," he said. Known to fans as "La Diva de la Banda" or The Diva of Banda Music, Rivera was well-established as a musical powerhouse with her Spanish-language performances of regional Mexican corridos, or ballads. For fans, the nickname captured her powerful voice and the personal strength many admired. In recent years, she had been working to crack the English-language U.S. market and was reportedly on the verge of a crossover with a sitcom inspired by the success of "I Love Jenni," a Spanish-language reality TV show on Telemundo's mun2 network. Rivera sold 15 million records, according to Billboard, and recently won two Billboard Music Awards, including favorite Mexican music female artist. In October, People en Español added her to its list of the 25 most powerful women. She performed at a concert in Monterrey on Saturday night before boarding the Learjet, which took off early Sunday and lost contact with air traffic controllers about 60 miles into the trip. Plane's owners tied to troubled businessman Just hours before she died, Rivera opened up to reporters about her divorce and the inner strength she found, thanks to her family. "I'm so happy. So many strong things have happened in my life," she said. "I can't get up in the negative, which destroys you." CNN en Español's Krupskaia Alis and Jaqueline Hurtado contributed to this report.