The firefighters of Ladder 35 went full force into the four-alarm fire that took over the Ingram Park shopping center late Thursday.
Fire crews responded to the blaze in the 6700 block of Ingram Road about 9:12 p.m.
After a mayday call for two lost firefighters, medical director David Miramontes said in an e-mail, RIT teams were sent in and rescued one, who's now in critical condition at San Antonio Military Medical Center Burn Unit.
Firefighters formed two columns and saluted as an ambulance departed the scene just after midnight.
Witnesses said people inside the shopping mall fled the flames.
"It was a very rough decision to leave a firefighter behind", an emotional Hood told reporters who gathered at the scene northwest of downtown.
So far, officials have not said what led to Deem's death.
The six-year department veteran was later found dead in the debris.
The cause of the fire is under investigation. "But we're going to continue to do the good job that we always do", Hood said.
Texas Gov. Greg Abbott issued a statement expressing sympathy to the fallen firefighter's family.
"My heart goes out to those firefighters that are out here trying to salvage our businesses, and I pray for them", Emond Johnson said.
They were inspecting the gym where the fire is believed to have started. "Those who put their lives on the line to serve others deserve our deepest respect, and we can never say thank you enough".
Fighting back tears during the media briefing, Hood asked for prayers for the fire department.