Interior Secretary Francisco Blake and seven other people died Friday when their helicopter crashed en route from the Mexican capital to nearby Cuernavaca, President Felipe Calderon's office said.

Killed along with Blake were four of his aides and the three-man air force crew of the Bell 407 aircraft, presidential spokeswoman Alejandra Sota told the media.

Authorities are investigating all possible causes of "this very regrettable accident," according to Sota, who said Calderon was meeting with Blake's family.

With a hand in everything from law enforcement to disaster relief and running elections, Mexico's interior department can be roughly described as a combination of the U.S. departments of Justice and Homeland Security.

The interior secretary is Mexico's second-most-powerful official after the president.

The 45-year-old Blake was a key figure in Calderon's struggle with drug cartels and organized crime, a conflict that has claimed more than 40,000 lives since the current head of state took office in December 2006.

Blake's death comes a little more than three years after the Nov. 4, 2008, plane crash that killed then-Interior Secretary Juan Camilo Mouriño.