The accident happened at the intersection of 6th Avenue and Laredo Street sometime after 7 p.m. Sunday.
According to Aurora Police, 37-year-old Doug Byrne was responding to a report of a 25-year-old Sedrick Maurice Niblet who was having a life threatening seizure at Hoops Park – only a block from the accident scene.
Authorities say Niblet later died.
Aurora Police said Officer Byrne lost control of his marked patrol car and was thrown from the vehicle and sustained injuries to his head and chest.
"Doug was speeding there to render aid to a citizen, which he has done throughout his police career," said Aurora Police Chief Daniel Oates at a press conference on Monday.
Byrne was taken to Swedish Medical Center where he died from his injuries.
Oates says for a while, the police force had hope that Byrne would pull through and about 50 officers held vigil overnight at Swedish Medical Center. They were given the news he had died around 2 a.m.
"This is a tragic accident," said Oates. "There is no criminal investigation."
On Monday, two officers were on the scene, examining the skid marks which had been highlighted with spray paint.
The skid marks lead to the median, where it appears the patrol car hit and flipped.
Police say they are trying to determine whether Byrne was wearing a seatbelt at the time of the crash, or whether the seatbelt may have malfunctioned, if he was wearing it.
"Department policy is that officers wear seatbelts, and it's common practice, due to the gun belts they wear, that they unleash their seat belt before they arrive," said Oates.
According to state law, police officers are exempt from seatbelt laws.
Neighbor Dan Cape says he saw a big emergency response to the accident.
"I came out on my front porch and saw numerous police cars coming up," said Cape. "Then the fire truck left – I guess they'd done what they could do. They were there for a couple of hours."
Neddra Niblet, Sedrick Niblet's former stepmother, says he was always playing basketball, was athletic and active and had no prior health problems.
"He was just the most loving, caring person that you'd want to meet," said Neddra.
Neddra says when she was told about his collapse, she raced to the park and on the way there, she came across the accident scene where Byrne was killed.
"I just thought that's where I was going when you saw the flashing lights and stuff," said Neddra.
She says when she did get to the scene where Sedrick was, police officers were still very attentive.
"The policemen at the scene where Sedrick died were very comforting and supporting of this family, at the same time though, you knew that they were very concerned about their fallen officer as well," said Niblet
An Aurora police officer, who asked not to be identified, told 9NEWS Officer Byrne was a great guy and he could not believe he was gone.
Byrne was an officer with the Aurora Police Department for three years and had previous law enforcement experience with the Glendale Police Department. Byrne was also a veteran of the first Persian Gulf War.
"We were fortunate enough to get Doug Byrne right out of the military in 1997," said Glendale Police Chief Victor Ross. "In the six years he was there, he touched everybody's life he came in contact with."
"He was a true hero," said Oates. "Absolutely dedicated to this community and this is a huge loss and we are hurting badly."
This is the second officer the Aurora Police Department has lost in the past year. Officer Mike Thomas was gunned down in September of 2006.
Thomas was on duty and sitting in his own car in plain clothes at the corner of Peoria Street and Montview Boulevard when police say Brian Washington shot and killed him. Washington has been charged with first-degree murder.
A gathering for Aurora Police officers is tentatively scheduled for Tuesday and Chief Oates says there may be a public memorial as early as Wednesday afternoon at the Aurora Police Department.
(Copyright KUSA*TV, All Rights Reserved)