Houston Fire Department says 2 children died during fire in Greenspoint area, grandpa severely burned while trying to save them

HOUSTON, Texas (KTRK) -- The Houston Fire Department is investigating a fire that it says left two children dead in a townhome.

Officials said the fire broke out at about 11 p.m. on Wednesday on Casa Grande Drive in the Greenspoint area.

"It's a very sad day for the department," HFD Chief Thomas Muñoz said.

Muñoz said the two children, their mother, and their grandfather were the only ones home at the time of the fire.

He added that both the mother and the grandfather had to be transported to the hospital on Wednesday night.

"We understand the grandfather made a valid effort to (try and save the kids)," Muñoz said. "He wasn't able to get all the way in."

Muñoz said the grandfather suffered severe burns while trying to rescue the kids.

The ages of those children haven't been release