Teammate and current world champion Kate Ziegler also missed out, a stunning result for the United States, which has won the event seven times since it was first contested at the 1968 games, including five straight from 1984-2000.
Hoff finished third in her heat, touching in 8 minutes, 27.78 seconds -- a whopping 8.08 seconds off her personal best time done in April. She wound up 11th overall.
One heat later, Ziegler was fourth in 8:26.98, which put her 10th overall. Only the top eight advance to the final. She was 8.46 seconds off her personal best done in March 2007.