DALLAS - Dallas Fire-Rescue is mourning the loss of a firefighter who died Thursday morning.

Chris K. Pham, 35, was found unresponsive at the fire station. Reports indicate other firefighters performed CPR.

He was rushed to Methodist Charlton Medical Center where he later died. The cause of his death remains unknown.

Pham is attached to Fire Station 49. He has been a firefighter since 2006. He was also engaged to be married.

Officials told News 8 that he was not fighting a fire or responding to a fire at the time he was found.

Loved ones and fellow firefighters of Pham gathered at the hospital upon hearing the news.

"One of the most traumatic experiences a fire department can have is losing a member of our family," said Chief Eddie Burns Sr., Dallas Fire-Rescue. "This morning, our hearts are broken following the loss of our brother, Chris Pham."

Pham had reportedly finished up a medical call Thursday morning and had returned to the station. He said he was tired and then took at nap. An hour later at shift change, he was found unresponsive.

"He was a bright and shining star and a future leader of the Dallas Fire Department.," Burns said.

Pham was engaged to his high school sweet heart. His family said they were unaware of any medical issues within the family.

His sister-in-law said he had told her just last week that he loved working as a firefighter and that he never wanted to leave the job.

There are five local agencies, including the Dallas Police Department, investigating the cause of his death. The DPD says they have not found any suspicious indications that contributed to his death.