Two construction workers freed after being trapped for hours in collapsed trench in Potomac, Md.

Rescuers pull free one of two men trapped in a trench collapse. (Photo: NewsChopper 7))

POTOMAC, Md. (WJLA/AP) - Dozens of rescue personnel worked for more than three hours to free two construction workers trapped up to the necks in mud when a trench collapse pinned them to the foundation of a home.

The accident occurred Thursday evening on Martingale Court in Potomac.

Montgomery County fire and rescue officials said the workers became trapped in a 15- to 20-foot trench while doing work on the home that required digging down to its foundation.

The workers were conscious and breathing throughout the rescue, which involved more than 50 workers.

"We were amazed that both of them walked out," said fire Chief Scott Goldstein.

Once they were removed, the pair were taken for evaluation by a University of Maryland shock trauma team.