Another person has died from burn injuries she received during the incident.
Lena Mock Knight, 65, was airlifted to the hospital Tuesday morning after a propane gas leak caused an explosion at the family's home in Dobbin.
She died from her injuries on Saturday.
Knight's 55-year-old sister, Jennifer Mock, died Thursday.
The third victim -- eight-month-old Wyatt Mock Smith -- remains in the hospital with brain trauma and burns to more than 50 percent of his body, officials said. Although he was severely injured in the blast, officials said his condition has improved and the family has been told his prognosis is good.
For more information on funeral arrangements or for information on how to help, visit the Montgomery County Fire Marshal's Office Facebook page.
In the wake of this week's tragedy in Dobbin, authorities said many residents may have concerns about the safe use of propane in their homes. For more information on propane safety, go to the Texas Railroad Commission website.