MASON CITY — A RAGBRAI participant from Sioux City, Iowa, has been found dead in his tent in Mason City in the second death during the weeklong bicycling event.

The Des Moines Register, organizer of the bike ride, reported 74-year-old George “Frank” Brinkerhoff was found dead inside his tent Thursday morning at Parker’s Woods Campground.

Mason City police Sgt. Greg Scott said Brinkerhoff was participating in the ride. Scott didn’t know if Brinkerhoff was riding alone or with a group.

Scott said Brinkerhoff appeared to die of natural causes, but a medical examiner who responded hasn’t determined the cause of death.

On Monday, 62-year-old Tom Teesdale, of West Branch, had a heart attack and died at a hospital in Emmetsburg.

There have been 30 deaths during RAGBRAI’s 42 years.