Mexican authorities were performing DNA tests Tuesday on remains believed to belong to Mexican-American music superstar Jenni Rivera and six other people killed when her plane went down in northern Mexico.
Investigators said it would take days to piece together the wreckage of the plane carrying Rivera and find out why it went down.
Authorities, meanwhile, began looking into the history of the plane's owner, Starwood Management of Las Vegas. Another of its planes was seized in September by the U.S. Drug Enforcement Administration in McAllen, Texas.
The U.S. National Transportation Safety Board said it was sending a team to help investigate the crash of the Learjet 25, which disintegrated on impact Sunday with seven people aboard in rugged terrain in Nuevo Leon state in northern Mexico.
Human remains found in the wreckage were moved to a hospital in Monterrey, the closest major city to the crash, and Rivera's brother Lupillo was driven past a crowd of reporters to the area where the remains were being kept. He did not speak to the press.
A state official, speaking on condition of anonymity because of the ongoing investigation, said investigators were testing DNA from the remains in order to provide families with definitive confirmation of the deaths of their loved ones.
Alejandro Argudin, of Mexico's civil aviation agency, said it would take at least 10 days to have a preliminary report on what happened to the plane.
"We're in the process of picking up the fragments and we have to find all the parts," Argudin told reporters on Monday. "Depending on weather conditions it would take us at least 10 days to have a first report and many more days to have a report by experts."
In an interview on Radio Formula, Argudin said Mexican investigators weren't sure yet if the Learjet had been equipped with flight data recorders. He also said there had been no emergency call from the plane before the crash.
Fans of Rivera, who sold 15 million records and was loved on both sides of the border for her down-to-earth style and songs about heartbreak and overcoming pain, put up shrines to her with burning candles, flowers and photographs in cities from Hermosillo, Mexico to Los Angeles.
Some Spanish-language radio stations played her songs nonstop.
"She really inspired us as female Hispanics to move forward in life," said fan Rosie Sifuentes at a vigil in Lynwood, California.
At Rivera's father's house in Lakewood, California, fans and neighbors walked up the driveway and hugged Pedro Rivera Jr., Jenni's brother.
A distraught Pedro recalled his last conversation with his sister at church when they were taking a collection to buy Christmas toys for needy children.
He said his sister gave him $5,000 to give to the children. "She said, 'I just want to see them smile. I just want to see them happy.' All she wanted was to see the happiness in people. And then she gave me a big hug. She said, 'I love you, brother.'"
He said he was later watching television and wanted to send a text message to his sister to say that he loved her. "But I didn't because I thought maybe she's busy, maybe she's just barely getting out of singing or something ... You just regret those moments."
Another brother, Juan Rivera, still held on to hope that his sister would be found alive.
"In our eyes, we still have faith that my sister will be OK. We have no confirmation of her body being recovered, dead or alive," he told reporters.
The California-born woman known as the "Diva de la Banda" died as her career peaked. She was perhaps the most successful female singer in grupero, a male-dominated Mexico regional style, and had branched out into acting and reality television.
A 43-year-old mother of five children and grandmother of two, she was known for frank talk about her struggles to give a good life to her children despite a series of setbacks.
She had recently filed for divorce from her third husband, former Major League Baseball player Esteban Loaiza.
Rivera recently won two Billboard Mexican Music Awards: Female Artist of the Year and Banda Album of the Year for "Joyas Prestadas: Banda." She was nominated for Latin Grammys in 2002, 2008 and 2011.
Besides being a singer, she appeared in the indie film Filly Brown, which was shown at the Sundance Film Festival, and was filming the third season of "I love Jenni," which followed her as she shared special moments with her children and as she toured through Mexico and the United States.
She also had the reality shows: "Jenni Rivera Presents: Chiquis and Raq-C" and her daughter's "Chiquis 'n Control."
Two of her five brothers, Lupillo and Juan Rivera, are also well-known singers of grupero music. Her parents were Mexicans who had migrated to the United States
The Learjet 25, number N345MC, with Rivera aboard was en route from Monterrey to Toluca, outside Mexico City, when it was reported missing about 10 minutes after takeoff.
The cause of the accident has not been determined
The plane was registered to Starwood Management of Las Vegas, according to FAA records, and was built in 1969.
According to the National Transportation Safety Board, the twin-turbojet was substantially damaged in a 2005 landing mishap at Amarillo International Airport in Texas. It hit a runway distance marker after losing directional control. There were four aboard but no injuries. It was registered to a company in Houston, Texas, as the time.
The company is also subject of a federal lawsuit in Nevada.
QBE Insurance Corp. alleges that a Starwood aircraft was ordered seized by the DEA when it landed in McAllen, Texas, from Mexico on Sept. 12. The New York-based insurer sued in October to rescind coverage for the Hawker 700 jet.
Starwood, in a court filing, acknowledged that the DEA was involved in the seizure of the aircraft.
QBE, based in New York, said the DEA also seized a Starwood-owned Gulfstream G-1159A — insured by another company — when it landed in Tucson from Mexico in February. Starwood said in its court filing that it didn't have enough information to address the allegation.
Nevada secretary of state records list only one Starwood officer — Norma Gonzalez — but QBE alleges that the company is owned and managed by Ed Nunez, who, according to the lawsuit, is also known as Christian Esquino and had a long criminal history.
Starwood rejected the insurer's description of Nunez's role at the company.
According to QBE's lawsuit, Esquino pleaded guilty in federal court in Orlando, Florida, in 1993 to conspiracy to possess and distribute cocaine.
QBE said Esquino also served two years in prison after pleading guilty to conspiracy to commit fraud involving an aircraft in Southern California in 2004. QBE said Esquino's attorney stated in court back then that his client had been under investigation by the DEA for more than a year.
Starwood said in its court filing that it didn't have enough information to address either the Florida or Southern California case against Esquino.
George Crow, an attorney for Starwood, did not immediately respond to phone and email messages left after business hours Monday.
There have been several high-profile crashes involving Learjets, known as swift, longer-distance passenger aircraft popular with corporate executives, entertainers and government officials.
A Learjet carrying pro-golfer Payne Stewart and five others crashed in northeastern South Dakota in 1999. Investigators said the plane lost cabin pressure and all on board died after losing consciousness for lack of oxygen.
Former Blink 182 drummer Travis Barker was severely injured in a 2008 Learjet crash in South Carolina that killed four people.
That same year, a Learjet slammed into rush-hour traffic in a Mexico City neighborhood, killing Interior Secretary Juan Camilo Mourino and eight others on the plane, plus five people on the ground.
Tamara contributed from Los Angeles. Raquel Dillon in Los Angeles and Elliot Spagat in San Diego contributed to this report.