SAN JOSE (AP) — A veteran San Jose firefighter who suffered a heart attack while battling a fire at a downtown cathedral last week remained in critical but stable condition, while his fellow firefighters kept a round-the-clock vigil at the hospital where he's being cared for, fire officials said Sunday.

Frank Ryan, who will turn 42 next month, collapsed around noon Thursday as he and other firefighters worked on containing a three-alarm blaze at St. Patrick's Cathedral, said San Jose fire spokeswoman Capt. Mary Gutierrez.

At the time he collapsed firefighters were working in "very hot, black-out conditions," Gutierrez said. Firefighters and witnesses said people inside the church ran from the building to escape the thick black smoke and the flames, while the students of a nearby elementary school were evacuated.

Witness Nguyen Nguyen told the San Jose Mercury News after the fire that he saw five people run from the church.

"Then there was smoke coming out of the side and the glass started popping out," Nguyen told the newspaper shortly after the fire.

Ryan, a 15-year veteran of the department, was assigned to the department's downtown fire station, one of San Jose's busiest, Gutierrez said.

"Frank would not have it any other way and prides himself in working at a busy fire company," Gutierrez said.

Ryan, who is not married, has three sisters and six brothers, Gutierrez said.

Family members are declining interviews, but in a statement the family said, "Frank is progressing in a positive way. We are taking it one day at a time given the circumstances surrounding his condition."

Firefighters were taking turns bringing breakfast, lunch and dinner to the family, friends and fellow firefighters who were maintaining the vigil at Regional Medical Center of San Jose, where Ryan is being treated, Gutierrez said.

Firefighters have also started a collection to help the family with expenses.

A prayer vigil was planned for later Sunday.

Officials said the cause and origin of the fire remains under investigation

Church officials have said they're not sure when the cathedral will reopen but have scheduled services at other locations.