This weekend, the 25th annual CHEO Telethon hits the airwaves on CTV.

This year's 24-hour telethon is set to begin Saturday at 7 p.m. on location at Nortel's Moodie Drive campus.

There will be musical guests, CHEO alumni, and some of the special people who give and get treatment. Watch it on cable, satellite, and for the first time, right here through streaming video on CTV Ottawa's website.

CHEO was built in 1974 because the community raised the money, and 25 years ago they showed how much they could give to make sure their kids got the best care.

But no one could have predicted that 25 years ago, a risky fundraising idea on live television would turn into the most successful telethon in North America and inspire a community.

Dan Holland, vice-president of finance for the CHEO Foundation was there in 1984 when CHEO became the first Canadian hospital to have a telethon joining the Children's Miracle Network.

"When I think back 25 years ago, we were trying to think, how are we going to do this? We had meetings every two weeks for months deciding how are we going to do this telethon," said Holland.

That is a moment Debbie Archambault, CHEO's finance director remembers vividly.

"There was a lot hinging on it for us to test the water and figure it out. There was a fear we were going to fail," said Archambault.

But those fears were proven false.

"We were sitting there and all these pledges were sort of dumped on our desks. They were massive and they didn't stop. Renfrew, Arnprior, Pembroke, Madawaska, they were just pouring in and we didn't realize we had touched those people," she said.

For those who didn't know about CHEO before, they did after the telethon.

"For every dollar that would come in, in my heart I knew ... that it was going to make a difference in the lives of the kids that were here," said Betsy Rouble, an employee at CHEO and also a parent of a son who needed CHEO's care.

The public couldn't seem to thank them enough.

"They would hang up the phone after they made their pledge and would say, 'Thank you for being there.' And you felt that you were somebody who had done something good," said Archambault

CHEO staff members agree the telethon helps to boost morale.

"I always come away from the telethon feeling we need to continue, we need to do more," said Renee Blouin, patient services director.

And the community also continues to do more. Over the years, the telethon has raised more than $59 million.

With a report from CTV Ottawa's Catherine Lathem