Now, the younger Summitt is out of a job and "profoundly disappointed in himself."
He announced his resignation Thursday, explaining he was doing so "for engaging in a relationship that has negatively affected people I love, respect and care about most."
Summitt did not elaborate on the nature of that relationship, or with whom it was, but did say he hopes now "to repair" others with people close to him.
"I am heartbroken that my time has ended in Ruston," he said, referring to Louisiana Tech's home. "But because of my respect for the institution, it is best that I resign."
Louisiana Tech athletics director Tommy McClelland told reporters Friday that the university had begun an investigation into allegations of an improper relationship before Summitt resigned.
"Dr. (Les) Guice and I met with Tyler at 10 a.m. (Thursday) ... and at the conclusion of that meeting he offered his resignation, and we accepted," he said.
The 25-year-old Summitt married Anne Dennis Ragsdale, his high school sweetheart, on June 1, 2013, according to his official bio
Louisiana Tech issued a statement on the resignation "effective immediately and for personal reasons" of its women's basketball coach over the past two seasons.
"The university has accepted his resignation and appreciates the contribution he has made to the growth and success of the Lady Techsters program," the school said.
Summitt grew up in Tennessee, where his mother emerged as one of the most successful and respected coaches in college basketball. There she won a record 1,098 games, more than any NCAA coach. Her women's teams won eight national titles and she was named the coach of the century in 2000.
She was diagnosed with Alzheimer's disease in 2011 and is now head coach emeritus at the Knoxville school.
Tyler Summitt spent two seasons as part of the University of Tennessee's men's basketball team, and also played a role in the Lady Vols' program from 2007 to 2009, a stretch that included two national championships.
After graduating, Summitt went on to serve two seasons as an assistant at Marquette University under Terri Mitchell.
He became Louisiana Tech's head coach in April 2014, hoping to turn around one of the sport's top programs after its first two ever losing seasons.
His record in two seasons leading the Lady Techsters was 30 wins and 31 losses. Summitt had just completed the second season of a five-year contract.
In a 2014 profile, Summitt told CNN he was trying to forge his own coaching identity.
"I don't dislike the comparisons to my mom," he says. "I just have the ultimate respect for my mom."
She initially had tried to steer her only child away from wanting to work on the basketball court. She knew well the stress, the commitment, the days away from family. Her view changed with time.
"I guess inside I always expected he would want to coach," Pat Summitt told CNN. "I just hoped, like any parent, that he would find something he loved to do."