The 16-year-old boy fatally shot near a Southwest Philadelphia basketball court Thursday night was a high school senior just weeks away from graduation, a standout basketball player, and something of a role model for younger teens in the neighborhood.

That’s how several people remembered Quamir Mitchell on Friday, the day after he was killed and a 13-year-old boy was wounded in a burst of gunfire near the Deritis Playground — a crime that police said remained something of a mystery in the early stages of the investigation.

Adrian Burke, Mitchell’s basketball coach at West Philadelphia High School, visited the crime scene Friday morning, on the 5600 block of Grays Avenue, to offer a prayer for Mitchell. Burke had known the teen for a decade, recalling his big heart, his love of basketball, his tendency to be “dressed to the nines.”

“He was phenomenal,” Burke said, tears pooling in his eyes. “Just a beautiful kid. He was so strong in his skin, and he knew who he was.”

Lawrence Martin, 70, who has lived in the area since 1985, said many young people in the community looked up to Mitchell, whom everyone called Day Day, and that some of them had been left shaken by the news of his death.

“Everybody loved Day Day,” Martin said. “There’s a lot of love for him in this community.”

The reasons behind the shooting remained unclear Friday. Chief Inspector Frank Vanore said a man was taken into custody Thursday night but was released and is unlikely to be charged. Vanore said detectives were still searching for surveillance video, witnesses, or other clues that could lead to a suspect or possible motive.

Commissioner Danielle Outlaw decried the shooting as “another incident of senseless gun violence” and said: “We must not allow these tragedies to become our new normal.”

Gunfire has been on a sustained and unrelenting surge in the city. Last weekend, seven people were killed and 18 were wounded in shootings, and on Wednesday, a 20-year-old man was killed in a quadruple shooting in Kingsessing — the latest example of how more and more incidents are leaving multiple victims injured or killed.

Already this year, 192 people have been slain in homicides, according to police — a 40% increase over the same date last year, and more than double the year-to-date total of 2016.

Twenty-one of this year’s homicide victims have been under age 18, police said, compared to eight juvenile victims through the same date last year.

In addition, more than 750 people have been shot this year, police said, a 39% increase over last year.

Earlier this spring, Homicide Capt. Jason Smith said police were seeing an especially troubling rise in violence among young people, much of which he said was being fueled by “petty nonsense” on social media.

Police said Thursday’s shooting was reported around 7:30 p.m., when officers were called to the scene and found Mitchell suffering from a gunshot wound to the chest. Police took him to Children’s Hospital of Philadelphia, where he was pronounced dead at 7:51 p.m., Vanore said.

The 13-year-old boy — whom police did not identify — was shot in the arm and was in stable condition, police said.

Monica Lewis, a spokesperson for the Philadelphia School District, said Mitchell’s killing was “a very difficult thing to deal with” for the students and staff at West Philadelphia High. The school held a virtual town hall Friday morning, she said, adding that “by all accounts, [Mitchell] was a very sweet and hard-working young man.”

“We as a community have to figure out a way to work together to help end these senseless acts of violence,” she said.

Burke, Mitchell’s coach, said Mitchell was a speedy point guard who stood about 5-foot-7 — short for a basketball player by most standards, but “with a big heart to make up for it.”

”He wasn’t scared of anything,” Burke said.

He said he spoke to Mitchell as recently as Wednesday, when Mitchell promised that he’d come to a summer league game next week.

There was little sign of a crime scene at the playground Friday morning, but word had trickled through the neighborhood. Women who darted away from their windows when gunfire rang out on Thursday evening gathered in the morning to lament the unrelenting gun violence, saying they worry that teenagers don’t have the after-school activities and job training opportunities they used to.

Martin, the longtime neighborhood resident, said the ability to access guns easily is like nothing he’s seen before. He said he worries about retaliatory violence and the ripple effect it can have.

”You got little kids who looked up to Day Day,” Martin said. “Now they’re scared.”