The story is so sensitive, long-time police and fire sources don't want to appear on camera -- even when they praise the firefighter, who drove the truck that hit the girl.
Forty-nine-year-old Elyse Duckett is known as a sharp, competent veteran of the fire department. Sources say several problems occurred, including those by other firefighters and top brass, which contributed to the tragic accident.
Duckett has been in the spotlight before -- in an award-winning documentary that mentions her career as a San Francisco firefighter.
Working out of the "crash house" -- station No. 2, right at the intersection of the runways, Duckett prepared 24 years for that day.
But, as her colleagues rushed to the crash site, sources tell say Duckett was out buying food for the firehouse . She came back to Station No. 2 to find everyone gone.
She jumped in a reserve Aircraft Rescue and Firefighting (ARFF) truck, Mobile 37.
Issue No 1: Sources say she drove by herself with no rider or spotter to help navigate. Department policy is to have two firefighters in the truck when fully staffed, but solo driving is allowed in an emergency.
"As it turns out, there was a small person stuck between the seats," San Francisco Fire Lt. Chrissy Emmons said in a July 8 press conference.
Duckett's fellow firefighters beat back the flames and boarded the aircraft, rescuing passengers.
"There were two non-ambulatory patients that we put on backboards, and one other person was basically just taken out of the plane," Emmons said.
Sources say a firefighter carried 16-year-old Ye Meng Yuan from the back of the plane and left her near the left wing, a hazardous place as the huge ARFF rigs jockeyed to fight the fire.
Issue No. 2: Whether the firefighter thought the girl was alive or dead, multiple sources say he should have gotten her to a safer spot.
"There was in the area where the victim was found a blanket of foam that was applied to suppress the fire on the aircraft," San Francisco Fire Chief Joanne Hayes-White said in a July 19 press conference.
The fire chief says a blanket of foam may have covered the girl, and Mobile 37, the truck Duckett was driving, did not have Forward Looking Infrared (FLIR) that can pick up a person's heat signature through fog, darkness, or even foam.
"And it reflects that on a screen in various shades of white or gray," San Francisco Fire Assistant Deputy Chief Dale Carnes said.
Issue No. 3: Carnes says his three frontline ARFF rigs have FLIR, but not reserve unit Mobile 37, even though the Federal Aviation Administration has funding available to retrofit rigs like it.
"As far as our reserve pieces, because we use them so rarely, it just hasn't been done," Carnes said.
Sources confirm the department told Duckett this week that it was the truck she was driving that rolled over Ye Meng Yuan and they offered her counseling.
The San Mateo County Coroner reported the girl died of blunt force injuries consistent with being run over.
"Those injuries she received, she was alive at the time," Robert Foucrault said in a July 19 press conference.
The ABC7 News I-Team has learned there are several videos taken by firefighters that have been passed on to the National Transportation Safety Board.
Issue No. 4: Sources say the videos show Ye Meng Yuan in a fetal position on the ground before Mobile 37 rolled over her -- several firefighters walk by, perhaps not realizing she needed help.
It is a tragedy on top of a tragedy. The airport fire chief says their investigation is wrapping into the NTSB's, so we may not hear the full story of what happened for a year.