Updated at 1 p.m. Saturday: Revised to include charges against suspects who survived.

A Fort Worth officer died less than a day after he was shot in the head when police confronted a group of serial robbers who held up a bar, authorities said early Saturday.

Garrett Hull, a 17-year veteran of the department, was critically wounded and the man who shot him was killed in a gun battle with police defending their mortally wounded colleague, authorities said.

Hull, 40, died of his injuries about 9:40 p.m. Friday, police said.

"We've lost a true hero," Police Chief Joel Fitzgerald said shortly after midnight Saturday. "Someone that has dedicated more than one tour of service to this great city was senselessly killed by three known criminals, two of which are in custody now."

Hull was with at least 10 other officers conducting surveillance on a group of people suspected in a series of robberies around Fort Worth, Sgt. Chris Britt said.

While the officers were at the scene, the group robbed the Los Vaqueros Bar in the 400 block of West Biddison Street, near Hemphill Avenue, Britt said.

"They bum-rushed the bar, told us to hit the floor. They had the guns out," owner Victor Zepeda told KXAS-TV (NBC5). "And as soon as they took off I heard gunfire. A lot of it."

Surveillance video obtained by NBC5 shows two hooded men running onto a patio where several customers sat drinking.

One of the robbers threw four men to the ground, pistol-whipping one of them. No one in the bar was seriously injured, police said.

Garrett Hull

The officers confronted the three suspects in the 3500 block of May Street. They fled on foot after unsuccessfully trying to get into a vehicle.

At least one of the three men fired at police, striking Hull in the head, authorities said. The officers returned fire, fatally shooting the gunman, later identified as 23-year-old Dacion Steptoe.

The two other suspects — Samuel Mayfield and Timothy Huff, both 33 — fled but were captured "in short order," the chief said. They each face 10 counts of robbery, according to Tarrant County Jail records. Both will also face capital murder charges for Hull's death.

Hull was rushed to John Peter Smith Hospital in a squad car because the scene was too dangerous to wait for an ambulance. Other officers performed first aid until they arrived at the hospital, Fitzgerald said.

"No other officers were physically wounded, but emotionally we're going to have to walk through this very carefully," he said.

It is with profound sadness that we must inform you that Officer Garrett Hull passed away Friday at 9:40 p.m. He was with family, friends and fellow officers. Please continue to pray for his family and those that need it in this tragic time.#RIP #PoliceFamily — Fort Worth Police (@fortworthpd) September 15, 2018

Fort Worth Mayor Betsy Price said the sacrifices of men and women like Hull often go unnoticed until they give their lives in the line of duty.

"The shock and the grief with terrible tragedies wake people up to the fact that many of our men and women serving don't go home," she said.

Fort Worth police say Dacion Steptoe (left) opened fire on police and was killed when they returned fire. Timothy Huff (center) and Samuel Mayfield were taken into custody and booked into the Tarrant County Jail.

The suspects in Friday's robbery were believed to be responsible for at least 15 robberies in Fort Worth and some in other cities, Fitzgerald said. During the course of those robberies, three people were wounded, the chief said, including one who had been shot in the head.

Hull, who is survived by a wife and two daughters, was part of a task force made up of uniformed and plainclothes officers, Fitzgerald said.

The robbers had become "progressively more violent" during the course of their crimes, and police acted quickly to intervene when they discovered the bar was being robbed, Fitzgerald said.

"I feel like I stand up here far too often and speak about officers being assaulted and officers doing their jobs trying to create a safe sense of community and cooperation and collaboration in Fort Worth, and being the victims of violent acts," Fitzgerald said. "We are certainly going to stand fast and be the beacon for the people out there who are victimized in our community."