It's official but still a secret — the entire cast from NBC's "Friends" will make a surprise visit at the 17th annual "L'Chaim – To Life!" telethon, set to air Sunday at 5 p.m. on KTSF Channel 26.

"Loosen your shoes and get ready for the high energy," said Rabbi Boruch Shlomo Cunin, West Coast director of Chabad.

Cunin's energetic stage presence during the telethon has earned him the nickname "the dancing rabbi."

Last year, the telethon received over $4 million in pledges from viewers all over the country. The money raised is used in charitable Chabad programs, including those aiding the homeless and the elderly.

This year's telethon, performed in Los Angeles, will be "the hottest," the rabbi declared, outlining a glittering guest list including James Caan, Shelley Winters, Elliot Gould and Sid Caesar.

He will not predict what viewers and participants can expect to see on the seven-hour program, "except for the record-breaking total on the tote board."

Since the first telethon aired in 1980, Jewish as well as non-Jewish superstars such as Bob Hope, Michael Douglas, Whoopi Goldberg and Edward James Olmos have been guests on the program.

Although the telethon has proved quite successful over the years, it was a tragedy that sparked the program in the first place.

In 1969, the Lubavitcher Rebbe, Rabbi Menachem M. Schneerson, founded the first Chabad House in a former fraternity building across the street from the UCLA campus. Shneerson said the house, which served as a house of prayer and a community center, should "serve as a key to open the hearts of all who visit."

Soon Chabad Houses were to open all over the country.

The rebbe's declaration was put to a strong test as drug use increased among America's young people. In 1970, Chabad recruited a staff of clinical psychologists to help people with drug problems. Thousands visited the house seeking aid.

Then, in May 1980, a fire destroyed the house. Three lives were lost.

"Avraham, a hippie whom we took off the street, perished in that fire," said Rabbi Yosef Langer from Chabad House in San Francisco.

"That fire was no accident and there was a question if the fire was racially inspired," said entertainer Ed Ames, who performed in the television series "Daniel Boone" and will sing at this year's telethon.

"After reading about the fire being racially inspired, I called Chabad in 1980 and said, `Anything I can do, I want to be a part of it.'"

Shortly after the fire, Schneerson is said to have urged his followers to turn the disaster into a source of strength in which to conquer new horizons.

That new horizon became the television screen.

"People in the entertainment world, such as Bob Dylan, Barbara Streisand and Jackie Mason — and others who were touched by Chabad over the years — came forward with enthusiasm in building a new and vibrant Chabad House," Langer said.

Chabad aired its first telethon that year, an event that later became known as the "L'Chaim — To Life!" telethon. Since then, the annual event has spread Yiddishkeit while performing tikkun olam [healing the world], said Cunin.

"The world is on positive wheels, thank God," he added.

"It will be an evening of phenomenal happiness. If you're giving 18 cents or 18 million dollars you will be giving happiness for many, including kids who can't afford to go to school. Thousands of letters are coming in with contributions. My son hopped in a taxi, and the driver said, `I'm so happy about this L'Chaim Telethon.' So my son asked, `Are you Jewish?'

"`No,' was his reply. `Five years ago, I was in your homeless program.'"