Rescue Effort Abandoned for Boston Business Man

The rescue of a Boston entrepreneur who fell into a deep crevasse while hiking in New Hampshire mountains has been abandoned.

Norman Priebatsch, 67, was on  hike with his son and two others on Sunday afternoon when he lost his footing on the White Mountains and fell into the crevasse.

His companions called for help after hearing no response from Priebatsch.

Jeff Lane, a snow ranger with the White Mountains Avalanche Center, was lowered 40 to 50 feet down into the crevasse, but could not go farther due to the space narrowing soon after Priebatsch's fall due to snow and ice.

Efforts were called off Tuesday because of increasingly treacherous conditions on the mountain, like long slides of ice, and hikers are being told to avoid the area.

"We are presuming it to be a recovery mission at this point,"  Lane told ABC News affiliate WMUR.

Priebatsch's family has scheduled a service for the missing man on Thursday at Temple Emmanuel in Newton, ABC News.com confirmed.

The crevasse located in Tuckerman Ravine is located on Mount Washington.  Each year an average of 25 people are injured on the mountain, according to the Mount Washington Avalanche Center.

On the day of Priebatsch's fall, the center reported frozen surfaces with the potential of dangerous sliding falls.

"The fact is, even very experienced mountaineers with all the right equipment would still have a very difficult time self arresting under the current conditions on some slopes in Tuckerman, so play it safe," wrote Lane in an avalanche advisory posted on the center's site.  Self-arresting is when a climber stops him or herself when sliding on a mountain.

Over the past couple of days, the avalanche advisories have warned of crevasses, undermined snow and waterfall holes as serious threats and recommended hikers to stay off the Tuckerman Ravine trail completely.

Priebatsch, a class of 1972 Harvard Business School graduate, co-founded a biochemical company called Adeptrix.  He also helped start a project called Tinnix, which used evaluation trials to determine if an iPhone app can evaluate the use of notched music as therapy to alleviate tinnitus.

According to his Tinnix biography, he enjoyed skiing, windsurfing, long distance running and hiking.  His wife Suzanne is an investment advisor at Smith Barney and his daughter Daniella works at Google in California.

Priebatsch's son Seth dropped out of Princeton to become the founder of the social networking site SCVNGR, a social based game where players can complete challenges at different places and earn rewards.