BRAZORIA COUNTY, Texas (CBSDFW.COM) – A Texas fire captain and his girlfriend were found dead inside a home Friday, and authorities are investigating their deaths as a murder-suicide.

The Brazoria County Sheriff’s Office told KTRK that deputies had responded to the home near Rosharon, just south of Houston, in regards to a welfare check from concerned family members. Authorities said they forced their way inside after hearing a child crying and no answer from adults.

Authorities said they found Joe Robinson, a Houston Fire Department captain, and his girlfriend, Briana Warren, dead inside the home, along with a weapon. Their 1-year-old son was found unharmed.

Joe Robinson (L) and Briana Warren (R) (Credit: Facebook and family photo)

While authorities did not confirm the cause of death, family members said they were told the two had been shot.

Family members said they believe it was a murder-suicide, but investigators are still looking into that.

Warren’s sister, Brandie, told KTRK that she had received a concerning text message from Briana. Brandie said she had rented a vehicle for her and that Briana was going home to get things in order to leave.

After not being able to contact her sister, Brandie said she and family members called 911.

“You would not have known. I’ve never seen this side of this man. I’m in shock,” Brandie Warren said.

Fire officials said Robinson was a 15-year veteran with the department and that he had just been promoted to captain last year.

“It’s a terrible family tragedy. We have two families one has lost a daughter the other has lost a son, and it’s heartbreaking,” Houston Fire Chief Sam Pena said.