Last week, there was a report that TSA Officer Gerardo Hernandez didn't receive medical treatment for 33 minutes after being shot. This caused some to question whether he could have survived.
Although Hernandez's autopsy hasn't been finalized, there was pressure to clarify when he died, Assistant Chief Coroner Ed Winter said Wednesday. More details were expected in a final report this week, he said.
Formal conclusions could take months, but what's known raises the possibility that a lack of coordination between police and fire officials prevented speedy treatment for victims.
Los Angeles Police Chief Charlie Beck said in a statement on Wednesday that the coroner's report shows Hernandez could not have been saved. He criticized "irresponsible" media reports.
"Some of the reporting on this incident was highly irresponsible. All the facts indicate that any action taken by responding officers or medical personnel would not have saved Officer Hernandez's life. What concerns me most about this is that it brought needless trauma to the grieving family members of Officer Hernandez."
Authorities say suspected gunman Paul Ciancia was targeting TSA workers in a vendetta against the federal government when he pulled a semi-automatic rifle out of a bag and shot Hernandez.
According to court documents, authorities say Ciancia fired repeatedly at Hernandez then went up an escalator, turned back to see Hernandez move, and returned to shoot him again.
He then fired on two other uniformed TSA employees and an airline passenger, who all were wounded, before airport police shot him.
Hernandez was eventually transported to an area hospital with no signs of life. Doctors worked for an hour to revive him.
A preliminary coroner's report said a bullet struck Hernandez's aorta, which would have caused the massive bleeding, according to a law enforcement official familiar with the findings speaking to the Associated Press on condition of anonymity.
Ciancia, 23, could face the death penalty if convicted of a federal murder charge. He was released from Ronald Reagan UCLA Medical Center on Monday and is now in federal custody.
The Associated Press contributed to this report.