CHICAGO — A Chicago firefighter has died after a house fire on the city’s South Side, officials announced Tuesday. Two other firefighters were injured.

The fire started inside a two-and-a-half-story home at 120th and Wallace in West Pullman around 3:30 a.m. Tuesday. Officials believe the fire started in the attic of the home, then eventually spread to its two neighboring buildings.

One of the firefighters was transported to Advocate Christ Medical Center in critical condition, where he later died. Fire officials have identified him as 49-year-old Jermaine Pelt, who had been with the department since 2005.

On Wednesday afternoon, his cause of death was released as carbon monoxide toxicity inhalation of smoke and soot due to working on putting out a residential fire.

“Jermaine was always willing to help anybody. He was very smart and ambitious but we’re going to miss him,” said John Pelt, the fallen firefighter’s father.

Official said it appears Jermaine Pelt went down as crews were being ordered out of the building. The firefighter’s lieutenant pulled him from the home and life-saving measures were performed in an attempt to save his life.

“Jermaine was very kind-hearted and we are going to miss him,” added David Bernicky with the Chicago Fire Department.

Two other firefighters are in stable condition, according to the department.

The home was vacant at the time of the fire.

Mayor Lori Lightfoot released the following statement on Twitter Tuesday morning:

I am deeply saddened to hear of the passing of Jermaine Pelt, an 18-year veteran of the CFD, who died early this morning in the line of duty. My heartfelt sympathies are w/ his family, fellow CFD colleagues, & his brothers & sisters of Engine 75 following this tragic incident. It takes a special form of bravery to work as a first responder, to rise to meet different disasters and dangerous situations on a daily basis. Jermaine put his life on the line to answer this call, a selfless act of bravery and dedication to the residents of this city. Our city mourns this tragic loss today, and is here to uplift all who loved Jermaine with our prayers and support.

Chicago Mayor Lori Lightfoot

Jermaine Pelt was the youngest of four boys. He was also a father of two; a 6-year-old boy and an adult daughter whom he walked down the aisle in November.

The cause of death is still under investigation. The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) is assisting the CFD in their findings.