Billionaire Richard Branson came within 'seconds' of death on Mont Blanc ascent

It sounded almost like heavy rain.

Rocks had started to tumble down Mont Blanc, the tallest mountain in the Alps, and billionaire mogul Sir Richard Branson and his son, Sam, sought shelter behind a boulder, he wrote on his blog.

Branson said a small rock skipped across his son's head, "loudly clipping" his helmet on the way down.

"A side of a cliff had…