Former Pinnacle Airlines CEO and prominent civic leader gunned down in Memphis Philip Trenary was also a prominent civic leader lauded for his community work.

Tennessee leaders mourned the death of a prominent civic leader and airline executive after he was shot to death on Thursday night.

Philip Trenary was the CEO of Pinnacle Airlines and served as the president and CEO of the Greater Memphis Chamber until his death.

He was alone on a street in downtown Memphis when a man parked his vehicle along a sidewalk, stepped out of it, approached him and then shot him, Lt. Karen Rudolph of the Memphis Police Department told ABC News in an email.

"It is still unknown whether this was a robbery or a personal vendetta," she added. "Investigators are still working to gather details relative to this investigation."

Trenary was shot near where the Greater Memphis Chamber was holding its annual “Move it Memphis” race.

The city's mayor, Jim Strickland, announced the death on Twitter, writing, "Like many of you, I'm shocked at the senseless loss tonight of Phil Trenary, a leader in our community."

Tennessee's governor, Bill Haslam, mourned the loss of a "wonderful friend" to his wife and a "great advocate for Memphis."

Trenary, 64, and an Oklahoma native, was lauded for his community work in his adopted city. He came to Memphis in 1997 to run a regional airline that morphed into Pinnacle, a $1 billion, 7,700-employee regional airline operator. He left the company in 2011, two years after which it became Endeavour Air.

"News of his passing is shocking and tremendously difficult to comprehend," the airline wrote in a statement. "Phil remained a steadfast advocate for the Memphis community and was a well-regarded executive and civic leader across Western Tennessee."

Trenary was named president and CEO of the Memphis Chamber of Commerce in 2014 and guided the launch of the chamber’s Chairman’s Circle, a group of more than 100 business leaders working to bolster the Memphis region.

Memphis police described the suspect in the attack as black, wearing a blue shirt, sporting dreadlocks and traveling in a white pickup truck with an extended cab and antenna.

"If anyone has any information pertaining to this incident, they are urged to call Crime Stoppers at 901901-528-CASH," Lt. Karen Rudolph said.

The Associated Press contributed to this story.