DALLAS - His week began thousands of miles away with a frantic bid to save a life.
It was Monday, Sept. 15, and Ebola, a terrifying disease, was ravaging West Africa, filling morgues and hospitals to capacity. In Monrovia, Liberia, the virus was about to claim one more person.
Marthalene Williams, seven months pregnant, had been diagnosed with low blood pressure when she was brought to a clinic, desperately ill.
Soon after coming home, she began convulsing. Thomas Eric Duncan, assisted by her family and others, lifted his neighbor into a taxi that rushed to a hospital maternity ward, where she was turned away. The 19-year-old woman returned to her house, where she died hours later.
That Friday, Sept. 19, Duncan arrived at Roberts International Airport in the capital of Monrovia.
He was about to embark on a three-leg journey, traveling from Africa, through Europe and into the United States. He would travel more than 8,000 miles before arriving at Dallas/Fort Worth International Airport in the early evening of Sept. 20.
His temperature, taken before he boarded the plane in Monrovia as part of precautionary government measures, had been below normal. But when he walked out into the steamy Texas night, he carried with him one of the deadliest diseases known to medicine.
Ten days later, he'd become the first person diagnosed in America with Ebola.
The same day that neighbors say Duncan carried his dying neighbor back into her home, the U.S. was calling for an emergency meeting of the U.N. Security Council to address the growing Ebola crisis.
The worst Ebola outbreak in history has swept through Liberia, Sierra Leone and Guinea, and has stretched into Nigeria and Senegal. Nearly 7,500 people are believed to have been sickened by the disease and more than 3,400 have died, according to the World Health Organization.
The first patient may to have Ebola in West Africa may have been a two-year-old boy who got sick and died in Guinea in December 2013. His mother, sister and grandmother reportedly died soon after, infecting others in the process.
It is unclear how the child might have caught it.
Liberia has been hardest hit, with more than 3,800 cases and slightly more than 2,000 deaths. But even those ghastly numbers likely underestimate the scope of the disaster and the true toll may never be known. The World Health Organization has noted that in the notoriously overcrowded slum of West Point, in the capital, bodies are just tossed into the river.
Liberia is woefully lacking beds in isolation units needed to care for people. Doctors Without Borders has described the heartbreaking act of turning away people who seek treatment at their centers in Monrovia.
The horrifying impact of Ebola can be seen and heard throughout Liberia's capital, from corpses on the street, men pushing the sick in wheelbarrows and the constant wail of ambulances. Even a public service phone message warns "Ebola is real" before a call comes through.
At the airport, nurses wearing white lab coats, face masks and gloves take the temperatures of departing passengers. There are giant dispensers with chlorinated water and buckets for hand-washing.
When Duncan arrived Sept. 19, his temperature was taken and recorded on a passenger screening form. It was 97.3 degrees Fahrenheit.
Citing the Ebola outbreak, the form notes: "We need your help to prevent the spread of this disease."
Ebola is transmitted through direct contact with saliva, sweat and blood. It is not contagious until the symptoms begin.
The form asks travelers if they have any of 10 listed symptoms - among them, fever, vomiting, diarrhea, stomach pain and fatigue. Duncan answered "no" to all.
He also was asked if he'd taken care of an Ebola patient or touched the body of anyone who'd died in an Ebola-stricken area in the last 21 days - the incubation period. He answered "no" to both questions as well.
It's unclear if Duncan knew he may have been exposed to Ebola when he boarded his plane. While he had close contact days before with the pregnant woman, who neighbors now believe died from Ebola, she was never tested. It was initially suspected she had died of complications from her pregnancy.
This past week, however, Liberian authorities announced plans to prosecute Duncan when he returns, accusing him of lying on the questionnaire.
Once in Dallas, Duncan settled in at the Ivy apartment complex in the northeast part of the city, which is home to thousands of immigrants, many of them poor. This melting pot where dozens of languages are spoken is less than a five-minute drive from some of the toniest sections of Dallas.
Duncan was staying in a second-floor apartment with Louise Troh, her 13-year-old son, Duncan's distant cousin and a family friend.
On Sept. 25, Duncan was feeling sick enough that he went to the emergency room at Texas Health Presbyterian Hospital. He was reported to have a fever, headache and abdominal pain, but no diarrhea or vomiting. The hospital said he told them he'd recently arrived from West Africa, but that he denied having been around anyone sick. He was released.
By Sunday morning, Duncan's condition had worsened.
Youngor Jallah, 35, the daughter of Louise Troh, went to her mother's apartment to check on him. He'd been vomiting and had diarrhea the previous night. When she arrived with crackers, Gatorade and tea, Duncan was too sick to come out for breakfast.
After she found him fully dressed with socks, shivering in bed under a thin polyester blanket, Jallah drove to a Wal-Mart to buy "the warmest blanket I could find." When she returned, she noticed red in his eyes.
Jallah, a nurse's assistant, took his temperature and blood pressure - both of which were unusually high - and called an ambulance. When it arrived, she warned the staff "this man is from a virus country." They returned in protective gear and gloves.
Now Jallah is in self-imposed quarantine with her partner, Aaron Yah, and four children in their modest two-bedroom apartment. She's wracked with regret for not taking precautions.
"I'm having all those bad feelings," she told The Associated Press. "I'm just doubting myself every minute. I'm trying to take my mind off it, but I can't do it." She doesn't kiss or hug her children, ages 2, 4 and 6, or her live-in partner's 11-year-old son or share dishes with them.
She says she and Yah, also a nurse's assistant, often work nights, and had left the children with her mother and Duncan every night of his stay.
The materials in Duncan's apartment had been there for three days after Duncan's diagnosis. There are questions as to why a hazmat unit was not ordered there sooner, reports CBS News correspondent Manuel Bojorquez.
Yah says he knows his active, affectionate children probably came in close contact with Duncan, but adds: "I know that with God, everything is possible, so I am just praying that nothing happens to them."
Duncan remains in isolation, where he was listed in critical condition Saturday.
At the end of the week, Texas health officials said they had narrowed to about 50 the group of people they were monitoring who had some exposure to Duncan. All are having their temperatures taken daily. So far, none have shown symptoms of the virus. Nine people who are considered to be at higher risk are being watched more closely.
Duncan has remained in contact by phone with some relatives, including Josephus Weeks, a nephew living in Charlotte, North Carolina. Duncan's mother is staying there.
"It can be scary sometimes and it can be uplifting sometimes," Weeks says of their conversations. "The days when I'm able to get him to smile, to laugh, those days are good. That means that he's feeling good and he's got a little more strength to fight."