Early Friday, she was shaking her head in disbelief at a top Trump administration official calling relief efforts in Puerto Rico a "good news story."
By the end of the day, San Juan Mayor Carmen Yulin Cruz was issuing a "Mayday" call for help for the U.S. citizens on the hurricane-ravaged island, decrying the administration's response to the disaster.
"I am mad as hell," said Cruz, standing in front of pallets of water sent for distribution. " ... We are dying here. And if we don't get the food and water into people's hands, we are going to see something close to a genocide."
When she studied public policy as a Carnegie Mellon University graduate student in the 1980s, Cruz learned to identify problems and solutions based on the evidence at hand.
As mayor of Puerto Rico's capital, she has been applying that approach in the wake of the devastation of Hurricane Maria.
In a Friday morning interview with CNN, she said: "This is, dammit, this is not a good news story. This is a people-are-dying story."
And she listed some of the evidence:
"When you're drinking from a creek, it's not a good news story. When you don't have food for a baby, it's not a good news story. When you have to pull people down from their buildings, because _ I'm sorry, but that really upsets me and frustrates me."
Cruz's response doesn't surprise Jon Nehlsen, associate dean at CMU, who met her about three years ago during a campus visit.
"She is a force of nature," said Nehlsen, of the Heinz College of Information Systems and Public Policy at CMU. "She's probably not 5'2", but she's this ball of energy, very charismatic. You can just tell she exudes leadership qualities."
Cruz, 54, is becoming one of the most recognized faces of post-hurricane Puerto Rico. She's seen in photographs embracing tearful survivors or sharing a moment of relief with residents lighting up donated solar lamps.
In TV interviews, wearing a baseball cap and sports shirt, she has issued increasingly urgent calls for aid and expressed frustration at delays. For example, 3,000 containers of food and medicine languished for days at port because there was no way to distribute them by truck on the island's devastated roads.
"I cannot fathom the thought that the greatest nation in the world cannot figure out the logistics for a small island of 100 miles by 35 miles," she said Friday afternoon.
"I am asking the president of the United States to make sure somebody is in charge that is up to the task of saving lives," she said. "If anybody out there is listening to us, we are dying and you are killing us with the inefficiency and the bureaucracy."
Donations of bottled water, meals and infant food were being sent to an outlying area where people had been drinking from the same creekwater they were bathing and laundering in.
"I am done being polite," she said. "I am done being politically correct. I am mad as hell, so I am asking the members of the press to send a Mayday call all over the world."
On Thursday, Elaine Duke, the acting U.S. Secretary of Homeland Security, had said the disaster response was a "good news story" because of "our ability to reach people and the limited number of deaths."
Duke muted her comments amid the controversy Friday, saying the good news was the people were "working together" but admitting to widespread struggles of people to find adequate food, water and fuel.
President Donald Trump has also drawn criticism for bringing up Puerto Rico's long-standing debt crisis in tweeting about the disaster response.
At least 16 people have been confirmed dead, with some estimates higher.
Cruz said power outages had put people with medical needs at risk, such as those relying on dialysis or oxygen tanks.
Cruz was born in San Juan and earned a bachelor's degree at Boston University. She graduated from CMU's Heinz College in 1986 with a master's of science in public policy and management.
Afterward she went to work in human resources at Westinghouse and other companies before returning to her home city and entering politics. She was elected to Puerto Rico's House of Representatives in 2008.
In 2012, she built a coalition that included advocates for the poor, good government, women and LGBT people to unseat the incumbent mayor.
She attibuted her win, despite a limited time and money, to shoeleather campaigning as well as skills she learned in school.
"What do you do with a big problem? You break it down into little problems, and you solve them simultaneously; that's the one thing I learned so well at CMU," she told the university publication CM Today in 2015.
