When Jacob Brown was 4 years old, his mother picked him up from day care and asked what he did that day.

“I can still see him climbing into the car and buckling up,” his mother, Theresa Brown, recalled. “Jacob said it was Martin Luther King Jr. Day and asked, ‘Did you know they told Rosa Parks to sit in the back of the bus?'” He was appalled. I knew then. It made me proud that he could feel that way and know that was wrong.”

It set the tone for the rest of his young life.

Brown, a standout athlete and valedictorian of South Portland High school’s class of 2015, died Friday of complications from a liver biopsy. He was 21.

“We’re in shock,” his mother said. “We are floating right now. We can’t believe it.”

His father is James Brown of South Portland, and he also leaves an older brother, Joseph Brown, and a tribe of loyal friends.

Brown was remembered by his parents Wednesday as a humble, smart, funny guy who had a profound impact on others during his short life.

He played soccer, basketball and baseball for South Portland High School. He and several of his Red Riots teammates grew up playing Little League together. In 2015, the power-hitting outfielder led the team to the Class A State Championship game against Bangor High School. The Red Riots fell short of the title, 5-4.

Todd Livingston, athletic administrator at South Portland High School, said Wednesday that Brown was an integral part of the team.

“He was very skilled, very tenacious,” Livingston said. “He was an all-around great athlete. He played the game the right way, with a smile on his face and good sportsmanship.”

Nick Troiano, Brown’s former teammate, said he was a clutch player and quiet leader.

“He led by example,” Troiano said. “Even in school … the kid was a brilliant. He was a genius. He had a ton of friends. Everyone liked him.”

Brown was valedictorian and recognized for outstanding achievement in honors math, biology and chemistry, and advanced placement statistics. He was a member of the National Honor Society, World Language Honor Society and an AP scholar.

His mother said he was humble about his achievements. She remembered attending his senior awards night.

“I didn’t even know he was first in his class until I got to the awards event,” his mother said. “Of course we were very proud.”

Brown received a scholarship to Boston College, but left after a semester to return to Maine.

He attended the University of Southern Maine and was pursuing a degree in nursing. His mother said he was looking forward to starting clinicals this fall at Maine Medical Center.

“We were so proud of him,” his mother said. “He would have made such a great nurse.”

Brown spent the summers of 2016 and 2017 working for South Portland Parks and Recreation at its Wainwright complex, painting and mowing athletic fields.

“Having played on the fields, Jacob understood the needs of athletes,” said Rick Perruzzi, recreation manager at Wainwright. “He was very good. He was motivated. I’d give him a daily list of tasks and he worked with very little direction. He caught on really quickly.”

Brown worked a couple of winters shoveling for his friend Troiano, co-owner of Troiano Property Services LLC.

He said Brown texted him a couple of weeks ago looking for work, though he was not feeling well at the time.

On May 13, Brown and his brother flew to Italy for two weeks. They rented a car and toured the region, staying at youth hostels and B&Bs. When they returned, Brown became sick. His mother said he had a fever, chills and rashes. He went to numerous doctors and underwent a battery of tests, but doctors were baffled. He got progressively worse.

Brown had complications during a liver biopsy procedure last week. Doctors performed a second procedure to stop the bleeding and Brown went into cardiac arrest.

His mother said she hopes his liver biopsy will give the family some answers. She expressed appreciation for the outpouring of support the family has received from the community.

Visiting hours will be held from 4 to 7 p.m. Friday at Conroy-Tully Walker South Portland Chapel, 1024 Broadway in South Portland.