It appears the health crisis is not quite over with yet.

Health officials announced two more deaths associated with swine flu Friday — a woman in her late 40s died last week in Arizona, and a 33-year-old Corpus Christi, Texas man died earlier this month.

Corpus Christi-Nueces County Health District's Dr. William Burgin Jr. said Friday that the man died May 5 or May 6 after becoming sick a few days earlier. The man's preexisting medical conditions, including heart problems, made it more difficult for him to survive any viral illness, Burgin said.

Burgin did not identify the man, but said he was a single parent of three children.

One of the children contracted swine flu but was treated and is recovering, he added.

Burgin said county health officials received confirmation Friday morning that the man had died of swine flu.

The death is the third from swine flu in Texas.

The woman who died in Arizona suffered from a lung condition, according to the Maricopa County Health Department.

In New York City, three more schools were shut down Friday where students have been sickened with swine flu symptoms. That brings the number of schools closed in the city to six. A city official says the new schools are in Queens and Brooklyn.

The latest closures suggest the virus is spreading quickly, although officials caution that the symptoms have generally been mild. However, an assistant principal is in critical condition with a confirmed case.

Mayor Michael Bloomberg said the assistant principal, Mitch Wiener, may have had pre-existing health problems — but on Friday, Wiener's son Adam said his father had only suffered previously from gout, which he said was unrelated to his current condition. He said his father is now suffering from kidney failure, pneumonia, dehydration and a lung infection.

"I don't know where people got that," Adam Wiener, 23, said Friday morning as he prepared to return to the hospital where his mother and one brother were holding a vigil.

Adam Wiener said his father had been sick since at least last weekend with flu-like symptoms "but we didn't think anything of it." Then early Wednesday, he said, the family called 911 after his father began "hallucinating and wasn't coherent."

Wiener's case marks the most severe illness in the city since the city's first known cases of swine flu appeared in late April. At least five schools in the city were closed then, but all have since reopened. Officials say the students who have fallen ill in this latest surge of illness appear to be experiencing mild symptoms, similar to routine flu.

New York City's first outbreak occurred when hundreds of teenagers at a Roman Catholic high school in Queens began falling ill following the return of several students from vacations in Mexico, where the outbreak began.

At first, the virus appeared to be moving at breakneck speed. An estimated 1,000 students, their relatives and staff at the St. Francis Preparatory School fell ill in a matter of days.

But the outbreak then seemed to subside. Additional sporadic cases continued to be diagnosed, but the symptoms were nearly all mild. The sick children recovered in short order and St. Francis reopened after being closed for a week.

The middle school with the confirmed cases is two miles from St. Francis.

People at the Susan B. Anthony school said students started going home sick on Tuesday and Wednesday, alarming parents.

"I'm worried," said Dino Dilchande, whose sixth-grade son goes to the school. "The city should have taken more precautions. We should have been notified earlier."

Administrators posted a sign on the door from the Health Department informing students and teachers that the school would be closed for a week. The school is in the Hollis section of Queens, a neighborhood known for producing several rappers including the group Run-DMC.

At the start of the flu outbreak in the United States, government health officials recommended that schools shut down for two weeks if there were students with swine flu. But when the virus turned out to be milder than initially feared, the Centers for Disease Control and Prevention dropped that advice but urged parents to keep children with flu symptoms home for a week.

So far, the virus has not proved to be more infectious or deadly than the seasonal flu.

CDC officials said schools may decide to close if there is a cluster that's affecting attendance and staffing.

Click here to visit FOX News' Swine Flu HQ.

The Associated Press contributed to this article.