Charles Bennett 1G, and Hedy Miller, a 22-year-old Boston nurse, escaped unharmed yesterday from a Schroder's Cave accident in Dolegville, N.Y., in which James Mitchell, 23, of Winthrop, died.

Bennett and his companions were exploring the cave, located ten miles east of Ithaca, N.Y., when Mitchell became wedged in a vertical shaft under a stream of extremely cold water.

Mitchell had lowered himself to the bottom of the shaft by means of a rope and pulley tied around his midsection. As he attempted to raise himself back to the opening of the chasm, he became stuck.

Bennett and Miss Miller, a former Wellesley student, worked for 45 minutes in temperatures of 10 to 20 below zero in an effort to free Mitchell. When all efforts failed, Bennett ran to a nearby farmhouse to summon aid. State and local rescue squads were soon at the cave site.

Although Michell was only 10 feet below Miss Miller and Bennett, he was more than 250 feet from the surface. Late yesterday afternoon, William Karras, of the National Grotto Rescue Squad, reached Mitchell and reported that he was dead. Karras stated that "the dirty part of this thing is he didn't get hurt--just cold."

First estimate of the temperature of the water in which Mitchell was continually bathed was 31 degrees. Rescue workers said it would probably take them two days to widen the chasm so the Mitchell's body can be removed.

Bennett said he met Mitchell and Miss Miller earlier in the week in Boston. When they found they had a mutual interest in cave exploring, they decided to investigate Schroder's Cave which was discovered by an Ithaca high-school principal, 25 years ago. Much of it has never been explored.