7:17 AM PT -- A family source tells us Willie had a flat tire at some point Tuesday, but allegedly got it fixed and continued to drive back home to Atlanta from Tennessee. The source says Willie crashed into a tractor trailer that was parked on the side of the road.
"American Idol" runner-up Willie Spence has died in a car crash ... a relative confirms to TMZ.
The singer was in Tennessee Tuesday when the crash took place ... although specifics of the accident have yet to be released.
Willie posted a video just hours before the crash ... doing what he does best -- singing his heart out. Douglas Now was first to report the story.
Fans of the show remember Willie blowing the judges away in season 19, and making it all the way to the finale ... singing hits like "A Change is Gonna Come" and "Georgia on My Mind." He ended up coming in 2nd place behind Chayce Beckham.
There's been an outpouring of love for Willie since his passing ... Katharine McPhee of 'AI' fame expressed her heartbreak -- saying, "God rest your soul Willie. It was a pleasure to sing with you and to know you."
The 2 performed a duet together during his time on season 19.