"He said that the conditions have gotten so bad that they're asking them to use the restroom in bags, and they were eating onion sandwiches," McKerreghan said.
The call was the last she has heard from them.
Much of the ship's electrical power went down in the fire, causing widespread malfunctions, including taking out sanitary systems.
Passengers have reported sewage sloshing around in hallways, flooded rooms and trouble getting enough to eat.
"It's disgusting. It's the worst thing ever," passenger Ann Barlow said.
"From what I understand, they're walking around in a lot of urine and fecal matter, and the sewers are backing up," McKerreghan said. Her doctor gave her antibiotics to give her daughter as soon as she gets on land. A checkup will follow as soon as possible.
Passenger Jet Hilton from Crawfordsville, Indiana, has relied on her sense of humor to get through the ordeal, her sister Jennifer Stanfield told CNN affiliate WTHR.
Four-thousand people on a stranded ship can't flush, Hilton jokingly messaged Stanfield, venting about the stench on board.
Hilton and 20 of her girlfriends booked the cruise to celebrate one of their birthdays.
She is a former cheerleader, Stanfield said, and is doing what she can to keep her group's spirits up.
The fire also cut power to air conditioning, and the ship is very hot, Stanfield said. Passengers are flocking to the deck for fresher, cooler air.
The crew has higher priorities to fulfill than cooling cabins with what electricity the ship does have.
"They have to make sure there's adequate power to keep the ship from sinking or burning further," said Dr. Richard Burke from the University of New York Maritime College.
The fire also knocked out the ship's stabilization system, causing it to list, Burke said.
"There's time when the ship is leaning pretty hard, and you're worried you'll flip," said passenger Donna Gutzman.
Bad luck before
The fire is at least the second problem for the ship since late January, when it had an issue with its propulsion system, according to a notice posted on the website of Carnival senior cruise director John Heald.
And it's not the first fire to disable one of the cruise line's ships.
In 2010, the Carnival cruise ship Splendor lost power after an engine room fire, leaving it drifting off the Pacific coast of Mexico. The USS Ronald Reagan ferried 60,000 pounds of supplies for the ship's passengers and crew as the ship was towed to San Diego.
For Laura Chavez, who was aboard the Splendor, news of the Triumph's debacle brought back unhappy memories. "That's exactly what we experienced," she told CNN. "It's very disappointing to hear that they're experiencing that again."
The Splendor's toilets also overflowed. "Oh, yeah, terrible, bad, bad, bad," she recalled. "We saw it coming through the seams, through the ceilings."
The 52-year-old flight attendant said she and her traveling companion took the cruise line's offer of a free trip, but news about the Triumph has soured them forever on Carnival. "I wouldn't want to go through that again," she said.
Food was in short supply then, too, she said. "At the very end, I was living on a box of Rice Krispies."
Another Splendor passenger said he was astounded that something so similar happened to the Triumph.