"I guess someone came to camp with the stomach flu and I think that's what happened," said Bella Collins, who was at Camp Seymour.
It didn't take long for what the Pierce County Health department believes is the Norovirus to spread throughout the sprawling waterfront camp.
Gunnar Sweem woke up ill, headed to the health office and found a long line.
"And just stood there and we kept throwing up and stuff," he said.
In all, 66 campers and 13 staff got sick.
"They said they felt a little better and came back and more throwing up happened," said Paige Sweem.
The YMCA says the tough but necessary decision was made to shut the whole place down.
"It's an unfortunate event," said Geoff Ball with the YMCA of Pierce and Kitsap Counties. "We're super disappointed that we have to end camp early."
As campers started complaining of stomach pain, the first area of concern was the kitchen. But it was ruled out as a likely source since it prepares lunches for YMCAs around the area and no one else got sick.
The county health department told the Y it's likely the Norovirus, which could have come in with a camper.
A third of the campers got sick and sent home immediately; the rest were entertained as they waited for parents to come pick them up.
"I'm relieved I'm not sick," said Rita Tumbusch. "So many people got sick."
Cleaning crews are scouring everything and a private company has been contracted to do a full sanitizing of the camp.
"It's difficult because they were having such a wonderful time," said grandparent Linda Cunningham.
The county health department says Norovirus has a 24-48 hour incubation period, so with the camp closed the next two days, they say it'll be safe to re-open Sunday in time for the next group of campers.