Former NFL tight end Vernon Davis is desperate for answers after Vontae Davis, his younger brother, unexpectedly died earlier this week, RadarOnline.com can reveal. Breaking his silence on Wednesday, Vernon revealed Vontae had just wrapped up a sauna session when he either collapsed or slipped at his Florida home. However, until the autopsy report is released, Vernon can only speculate about what may have caused his brother’s death. “This thing definitely caught me by surprise,” Vernon, 40, told Daily Mail. “I just don’t know what to make of it.” He said Vontae recently seemed to be healthy an…