The death of Miss Hawaii Teen United States Sheryl Wolfe in April was the result of a freak accident, the city Medical Examiner's Office said yesterday.

Adding a sad new dimension to the case, doctors say a head blow set in motion a deadly chain of events that likely could not have been countered.

The Mililani student struck the back of her head on a wooden sofa post at home, causing her to die from a stroke the next day, said forensic pathologist Kanthi de Alwis.

The sudden blow caused a tear to the inner lining of a neck artery, eventually leading to a blood clot, she said. When the clot broke free, it cut off blood circulation in the brain, leading to an ischemic stroke.

De Alwis, a former medical examiner who is working for the agency, said that kind of fatal accident is rare and that it is the first time she has come across it in her decades of experience.

Within 12 hours after the accident, Wolfe collapsed in her class at Mililani High School on April 13. She was ruled brain dead on April 16 and died April 19.

De Alwis said Wolfe told her sister at the time of the accident that she felt her eyes were going to “;pop out,”; but the teenager did not show any of the symptoms associated with trauma, such as nausea or a headache.

“;Even if she had gone to the hospital, it wouldn't have been detected,”; De Alwis said. “;It would have taken some time for the body to react. ... It was a stroke but not a natural stroke. It was a so-very-tragic accident.”;

Wolfe, 18, whose memorial service was held Friday at Mililani High School, won the Miss Hawaii Teen United States title in June 2009 and was planning to pursue a modeling career, said Luana Alapa, the pageant's state director.

“;We're still in shock. I still can't get over it,”; Alapa said. “;She was so young, beautiful, lively. Everyone was drawn to her.”;

Alapa said Wolfe was a talented piano player, composed her own music and was an excellent graphic designer.

She also held the title Miss Hawaii Teen Princess.