Rome, July 29 - Italian President Giorgio Napolitano said on Monday that he was "deeply saddened" by the bus crash in southern Italy that killed at least 38, possibly 39, and seriously injured 10 others overnight Sunday. "This tragedy reminds us of the need for a more decisive commitment to road-safety initiatives to reduce risk factors. Maintenance and driver checks must be scrupulous...to protect ourselves, our loved ones and others," Napolitano said. Police are investigating the braking system and tires of the bus carrying a group of friends that fell some 30 meters from a viaduct. The group was returning from a weekend excursion to the local Telese thermal baths and the popular pilgrimage destination of Pietralcina, home town of the Italian saint, Padre Pio. Police investigating said that there were no skid marks indicating that the driver had braked. The driver bumped into six cars before the bus slammed into the guardrail and flew from the high viaduct, police said.