Wife of Grant Wahl, American journalist who died at World Cup, reveals cause of death

American soccer journalist Grant Wahl died of a "slowly growing, undetected" ascending aortic aneurysm with hemopericardium, a New York City medical examiner autopsy found, according to Wahl's wife, Dr. Celine Gounder.

Wahl died while covering the FIFA World Cup in Qatar. He was 48.

Wahl "fell ill" while covering the Argentina-Netherlands quarterfinal, a spokesperson for the Qatari World Cup planning committee told Fox News. After paramedics performed CPR for several minutes at the scene, he was taken to Hamad General Hospital.

Wahl had been "laughing at a joke we saw on Twitter" just minutes before reportedly collapsing, journalist Rafael Cores, who was sitting next to Wahl at the game, said.