PHOTOS: Firefighters gather to say goodbye to fallen Pittsburgh Fire Battalion Chief John Walsh

Family, friends and firefighters gathered at St. Paul Cathedral in Oakland to say goodbye to Pittsburgh Fire Battalion Chief John Walsh, who died of a medical emergency while in command of a fire scene.

Long and somber procession goes to St. Paul Cathedral

Family, friends and firefighters gathered at St. Paul Cathedral in Oakland to say goodbye to Pittsburgh Fire Battalion Chief John Walsh, who died of a medical emergency while in command of a fire scene.

Procession takes Chief John Walsh to funeral Mass

Family, friends and firefighters gathered at St. Paul Cathedral in Oakland to say goodbye to Pittsburgh Fire Battalion Chief John Walsh, who died of a medical emergency while in command of a fire scene.

Firefighters gather outside St. Paul Cathedral

Family, friends and firefighters gathered at St. Paul Cathedral in Oakland to say goodbye to Pittsburgh Fire Battalion Chief John Walsh, who died of a medical emergency while in command of a fire scene.

Battalion Chief Walsh remembered as "top-notch firefighter"

Family, friends and firefighters gathered at St. Paul Cathedral in Oakland to say goodbye to Pittsburgh Fire Battalion Chief John Walsh, who died of a medical emergency while in command of a fire scene.

Pittsburgh fire trucks hold American flag

Family, friends and firefighters gathered at St. Paul Cathedral in Oakland to say goodbye to Pittsburgh Fire Battalion Chief John Walsh, who died of a medical emergency while in command of a fire scene.

Battalion Chief John Walsh's casket is carried into church

Family, friends and firefighters gathered at St. Paul Cathedral in Oakland to say goodbye to Pittsburgh Fire Battalion Chief John Walsh, who died of a medical emergency while in command of a fire scene.

Firefighters from all over come to pay their respects

Family, friends and firefighters gathered at St. Paul Cathedral in Oakland to say goodbye to Pittsburgh Fire Battalion Chief John Walsh, who died of a medical emergency while in command of a fire scene.

John Walsh remembered as "a firefighter's firefighter"

kdka-pittsburgh-bureau-of-fire-chief-john-walsh-funeral-obituary.png — Slater Funeral Service

A funeral service is being held Monday for Pittsburgh Bureau of Fire Battalion Chief John Walsh, who died last week of a medical emergency while in command of a fire scene in the city's East Hills neighborhood.