Indiana police lieutenant shot dead while helping at crash scene The death of Lt. Aaron Allan has left the law enforcement community grieving.

 -- An Indiana police lieutenant was shot and killed while trying to help at the scene of a car crash on Thursday, authorities said.

The Indianapolis Metropolitan Police Department said the death of Lt. Aaron Allan of the police department in Southport, just outside of Indianapolis, was the department's first line-of-duty death.

The shooting happened Thursday at about 2:30 p.m., when Allan and an officer from the Homecroft Police responded to a report of a crash, the Indianapolis Metropolitan Police Department said.

"As Lt. Allan approached the inverted vehicle to assist, shots were fired by one of the vehicle's occupants," police said in a statement.

According to ABC affiliate RTV6 in Indianapolis, a witness at the scene said the driver was upside down in the car when he began shooting at Allan.

The Homecroft police officer "and an off-duty Johnson County Sheriff's Deputy, who had stopped to help, returned fire striking one of the individuals," police said. "Both people inside the car were taken to Eskenazi Hospital, one for injuries sustained from being shot, and the other from injuries believe sustained during the crash."

Allan, 38, a husband and father, was hospitalized and later died, police said.

Jason Brown, 28, of Indianapolis, was arrested on suspicion of murder, according to police, though he has not yet been formally charged. The Marion County Prosecutors Office will make a charging decision, police said, calling the investigation ongoing.

The car's passenger was interviewed as a witness and released by police, authorities said.

Allan's death has left the law enforcement community grieving.

He had over 20 years of law enforcement experience and nearly six years of service with the Southport Police Department, the police said.

According to RTV6, Southport Police Chief Thomas Vaughn said of Allan, "When a citizen or someone needed help he was one of the first guys that was always there. ... He was involved in the community and he was involved in reaching out to the youth."

In 2015, Allan was named Officer of the Year after saving two lives the year before, RTV6 reported.

"They had a guy in cardiac arrest when he was working part-time at the fairgrounds and he saved his life," Vaughn said, according to RTV6. "He also had another incident where someone had overdosed on heroin and he was there with [overdose antidote] Narcan. He searched for about two hours in the rain to find her."

"His mom told me today that he'd always wanted to be a policeman," Vaughn said, according to RTV6. "He took that to heart."

The Southport Police wrote on Twitter, "Please keep Lt. Allan and his family in your thoughts."

The Indiana State Police tweeted, "We grieve with @SouthportPD over the loss of Lt. Aaron Allen."