Truett Foster McKeehan, the oldest son of Christian rapper TobyMac, died Wednesday in Nashville, a representative confirmed to the USA TODAY Network - Tennessee. He was 21.

The Nashville Fire Department responded late Wednesday morning to a report of a person in cardiac arrest at a home in the city's Radnor neighborhood. McKeehan was pronounced dead on arrival.

McKeehan's cause and manner of death remain under investigation, the Metro Nashville Police Department said. An autopsy will be conducted at the medical examiner's office in Nashville.

TobyMac, known also as Kevin Michael McKeehan, postponed the remaining dates of a week-long Canadian tour to return home to his wife and other children in Franklin, Tennessee.

In a statement, TobyMac said his son "had joy that took the room when he entered."

"He was a magnetic son and brother and friend. If you met him you knew him, you remembered him. His smile, his laugh, the encouragement he offered with words or even without. He had an untamable grand personality and dreams to match."

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An aspiring rapper

Truett McKeehan was an aspiring rapper who collaborated with his father under the moniker truDog. TobyMac included truDog on multiple songs, including 2007’s “Hype Man (truDog '07')” and 2010’s “LoudNClear.”

Truett McKeehan released music under multiple pseudonyms, including TRU, Moxie, Shiloh and Truett Foster. A music video for a Moxie song called “Eyes” was uploaded to Truett Foster’s YouTube account in June.

TobyMac also spoke of his son's talent as a musician who wrote, recorded, mixed, produced and designed everything himself. He said that his son's music and lyrics were very different from his own, but said he "always had a soft spot for God."

"The Bible moved him. His heart was warm to the things of his King. He was by no means a cookie cutter Christian but give me a believer who fights to keep believing. Give me a broken man who recognizes his need for a Savior every time. That’s who Truett was and how he should be remembered."

He played his first concert last Thursday at the Mockingbird Theater in Franklin. TobyMac said the performance was "nothing short of electric," and that it was the last time he saw his son.

"As I stood in the audience and watched my son bring joy to a room, I was as proud as a 'pop' (as tru called me) could be. It was the culminating moment of a dream that he had since he was 12. It couldn’t have been sweeter. Our music, and what we say lyrically couldn’t be more different, but the outcome was much the same… offering a room full of people a few minutes of joy in a crazy world."

TobyMac song 'Scars' details relationship with Truett McKeehan

Last year, TobyMac released a song called "Scars" that reflected on how his relationship with his eldest son started changing when Truett McKeehan left home.

The artist told The Tennessean last year it was tough to see his oldest living on his own.

"Up to now, (our home has) been a safe harbor, a place of love. And now, you know, I have my first kid leave home. He's going and facing this world. ... To watch and see him get cut and get bruised, it's not easy," he said.

After his son's debut performance, TobyMac texted him to tell him how proud he was. McKeehan responded: "love you dad...thank you so much...you have always believed in me...make me feel like a superhero"

Community support

Truett McKeehan's friends started posting memorial messages on the last post on the truettfoster Instagram page Wednesday afternoon.

"I hope you are having the time of your life with the big guy in the sky," one wrote.

New Hope Academy in Franklin, a Christian school supported by TobyMac and his family, said in a statement that Truett McKeehan “left an indelible mark on all of our students and faculty.”

Truett McKeehan attended New Hope until he graduated 6th grade in 2011.

“He was kind-hearted, creative, joyful and welcoming,” the statement said. “He lit up every room that he entered, and his presence among us will be deeply missed.”

The Nashville music community offered an outpouring of support Thursday for TobyMac and his family.

Community reacts:Christian music community mourns death of 21-year-old Truett Foster McKeehan

Gospel artist and TobyMac collaborator Mandisa shared lyrics to "Scars” on Twitter and Rascal Flatts vocalist Gary LeVox urged his followers to “please cast a prayer over the family.”

Christian artist Danny Gokey shared: “I can’t imagine what it’s like to lose a child. They absolutely need our prayers. Just like Arron & Hur lifted up the hands of Moses in battle, we need to lift this family up and be there for them through prayer.”

In his statement Thursday, TobyMac said, "My wife and I would want the world to know this...We don’t follow God because we have some sort of under the table deal with Him, like we’ll follow you if you bless us. We follow God because we love Him. It’s our honor.

He is the God of the hills and the valleys. And He is beautiful above all things."

Funeral arrangements were not available at the time of publication.

Tennessean reporter Natalie Neysa Alund contributed to this article.

Reach Brad Schmitt at brad@tennessean.com or 615-259-8384 or on Twitter @bradschmitt.