VANCOUVER -- Jon Witt says it's only "by the grace of God" that he and his extended family are still here today.

He was one of 21 people who were onboard a houseboat on Mara Lake that erupted into flames in the early hours of Tuesday morning.

The group are all extended family and had travelled to B.C. from Saskatoon. Witt is an emergency physician who grew up in Salmon Arm in the Shuswap Area. He and many others in the group have been working on the pandemic response, so this trip was meant to be a relaxing summer vacation.

"There was a houseboat malfunction and a catastrophic fire and it was just, you know, by the grace of God and good luck that we got out of there seconds ahead of that whole boat going up," Witt told CTV News Thursday night.

The group rented a 75-foot vessel from Sicamous Houseboats and boarded on Monday afternoon. Witt says they spent the day swimming and playing on the water slides off the back of the boat. When night fell, they parked on the beach and everyone made their way to bed.

Witt said he decided to start running the generator because they had "been running a lot of power, a lot of air conditioning and everybody wanting a shower and I was a little worried that the batteries were getting run down."

After an hour and a half, the generator started to click on and off, then it shut off altogether, killing power to the boat.

Witt said for some reason, he stayed awake that night. He opened the door of the back deck to check what had happened.

"I was just hit with a blast of heat and smoke... that plastic smell, that really toxic smoke," he said. "The flames were coming out from under that generator compartment and the whole area around the whole back deck was on fire and the heat was overwhelming."

He yelled for everyone to get off the boat – seven parents, six teenagers and eight children, including a one-year-old. In the dark, they made it to the beach.

"There were flames 30-40 feet high in the air," Witt said. "Honestly, another 30 seconds … we may not have made it out of there, certainly not everybody would have made it."

Anna Weibe is one of the teenagers who were onboard. She helped some of the younger children get off  the boat safely.

"We were as lucky as we could possibly be, and even the tiniest little things could have just made it so different, I was thinking the car ride home would be such a different car ride."

Her grandfather, Michael Murphy, is a retired professor who taught education at the University of Saskatchewan. He wasn’t on the boat, but all his 11 grandchildren were.

"Were it not for Jon Witt, they all would have died within a matter of minutes," Murphy said. "There was a possibility of my witnessing the burial of 16 of my immediate family, 16 people. They're all safe, they're all here, the boat's gone but they are all here."

Witt says none of the smoke detectors went off, and one of the daughters in the group found a dismantled smoke detector in one of the drawers.

CTV News reached out to Sicamous Houseboats and received the following statement in reply:

"The crew at Sicamous Houseboats are so grateful that the families on board the Wade James got off safely. The firefighters and EMS were quick to respond and minimized the danger and fire spreading. Thank you to them. We do not know the cause of the fire and we are working closely with the fire commissioner to determine the cause. Safety is our number one priority at Sicamous Houseboats for both our guests and our staff."

The company also said that its boats receive "thorough inspections of all mechanics and maintenance with each return and departure," and that the boat's systems were "functioning at a safe level" when it departed on the night of the fire.

Ian Gilson is a Director with the Canadian Safe Boating Council. He says this incident is "tragic" and accountability should rest on the company. 

"Commercial companies have the responsibility to make sure that the boats that they rent are in tip top condition because often times they’re renting to first time boaters," Gilson said. "They should make sure that everything has been thoroughly checked over and all of the electronics are."

Salmon Arm RCMP say if an investigation opens, they will issue a news release about it. A representative from the Transportation Safety Board told CTV News it does not investigate incidents on pleasure crafts.