The mass charity bicycle ride Levi”s GranFondo took a tragic turn Saturday morning when a rider was killed in a crash on a winding section of road north of Cazadero.

Few details were immediately available, but California Highway Patrol Sgt. Robert Boyer confirmed the death of a rider near Hauser Bridge.

“There have been several serious injuries today,” Boyer said.

Hauser Bridge spans the south fork of the Gualala River on Hauser Bridge Road, a steep, winding road at the northwest corner of the GranFondo course.

Carlos Perez, owner of Bike Monkey, the ride”s producer, said he needed additional time to gather information about the incident. But he said over 28,000 riders have completed that section of the course over the event”s seven-year history, and organizers do a great deal to warn riders about the dangerous sections.

“That”s why it”s blowing my mind that someone could crash like that,” Perez said.

Perez said he expected to make an announcement about the crash at the post-ride festival at around 3:30 Saturday afternoon.

“Everybody”s already talking about it,” he said.

He said the victim was a white man from out of the area, but that the CHP had provided him no additional information about his identity.

The accident is the first fatality in the event”s history. More than 6,000 riders were participating this year.

There were numerous calls for medical aid during the morning including report of a rider with a broken collarbone.

2015 The Press Democrat (Santa Rosa, Calif.)