TAMPA — A respected mural artist died at Tampa General Hospital on Friday after sustaining a severe blow to the head in a fight outside a South Tampa bar earlier this week.

Matt Callahan, 40, owner of Man Made Murals in St. Petersburg, was rushed to Tampa General Hospital on Wednesday.

He was listed on patient rolls early Friday evening but detectives were already calling their inquiry a death investigation, said police spokesperson Steve Hegarty. At 8:30 p.m., the hospital confirmed that Callahan had died.

Police found him on his back with head trauma just after 3 a.m. Wednesday in a median on Gandy Boulevard in Tampa.

He was unresponsive and his breathing was shallow, Hegarty said. Tampa Fire Rescue rushed him to TGH, where he was initially listed in critical condition with bleeding to his brain, Hegarty said.

The injuries occurred in a fight, Hegarty said. Detectives have not yet determined who started the fight, but they are talking to people who were involved, he said.

Minutes before the encounter, Callahan was inside the Warehouse Liquor Store and Bar on the corner of Gandy Boulevard and Clark Avenue, according to a police report.

An employee of the bar told police that Callahan and other patrons argued. The worker did not see what happened after they went outside, the report said.

Callahan, who lived on Pearl Avenue in Tampa, had owned Man Made Murals since 2002.

His work can be seen on brick walls and tin siding in Tampa and St. Petersburg. One mural he painted with Angela Delaplane in 2015 called "St. Tampasburg'' covers the back alley wall of The Lure restaurant, 661 Central Ave., and depicts scenes from the two cities' histories.

In March, he posted on Facebook about doing a 20-foot by 25-foot mural officially announcing the NCAA 2019 Women's Final Four Tampa Bay.

On April 6, he posted about Perennial Bloom, a festival of music and art that night in St. Petersburg. "80 plus artists tonight in St Pete, come see the show!" he wrote.

He attended Florida State University and the Atlanta College of Art.

His 2,364-person friends list captured a cross section of the bay area, leaning toward creative spirits and the people who appreciated them.

Contact Jonathan Capriel at 813-225-3141 or jcapriel@tampabay.com. Follow @jonathancapriel