Summary:
Mexican authorities are investigating the killing of a well-known singer in a suspected hit-and-run case.

Full article:
(CNN) -- A group of gunmen killed a well-known Mexican singer when he arrived at a toll booth in the western Mexican state of Sinaloa, state media said. The Deputy Attorney General's Office said Sergio "El Shaka" Vega was on his way to perform at a village festival concert when gunmen ambushed the red Cadillac he was driving around 9:30 p.m. Saturday (12:30 a.m. Sunday ET), Mexican state news agency Notimex reported. Authorities are still investigating the 40-year-old musician's death. They said they found 9 mm shell casings in the car's door, Notimex reported. Musicians have been targets of Mexican drug gangs in the past. Violence in Mexico has skyrocketed since President Felipe Calderon declared war on the nation's drug cartels shortly after taking office in December 2006. More than 22,000 people have died in drug violence during that time period, the government said recently. CNN's Esprit Smith contributed to this report.