A Southport, Indiana police officer was shot and killed Thursday as he tried to help at the scene of a car crash.  

Lt. Aaron Allen, an officer from the Homecroft Police Department, responded to the report of a car accident at approximately 2:30 p.m. As the officers approached the flipped over vehicle, one of the occupants of the car opened fire, reports ABC News.

A witness at the scene told RTV6 that “at least 20” shots were fired as the driver was upside down in the vehicle.

The Homecroft police officer and an off-duty Johnson County Sheriff’s Deputy who had stopped to help returned fire, hitting one of the individuals in the car. Both occupants were taken to Eskenazi Hospital – one for injuries sustained in the crash and the other for gunshot wounds, reports ABC News.

Lt. Allen, 38, was hospitalized and later died of his injuries. He was a six-year veteran with the Southport Police Department and had nearly 20 years of law enforcement experience, reports WTTV. He leaves behind a wife and children.

Twenty-eight-year-old Jason Brown of Indianapolis was arrested on suspicion of murder, though he has not yet been formally charged. The car’s 20-year-old passenger was interviewed and released. Authorities told ABC News the investigation is ongoing.

According to RTV6 , Brown is a tattoo artist and father to a three-year-old boy.

Lt. Allan was named Officer of the Year in 2015 after saving two lives in 2014. Southside Mayor Joe Hogsett issued a statement Thursday addressing the tragedy:

“Together, our community grieves for the Allan family and for all the men and women who risk their lives on a daily basis to protect our city and its citizens.”

A GoFundMe page has been established for the family of Lt. Allan and has raised over $23,000 as of press time.

Feature photo: GoFundMe