An 18-year-old who was two weeks from graduating from Overbrook High School and set to attend Kutztown University this fall was fatally shot in West Philadelphia on Tuesday, one of two teenagers killed in the city within an hour of each other.

Nasir Marks, of Overbrook Park, spent the evening practicing a speech on diversity in America — his senior project — in front of his mother and brother, his family said. He slipped on a hoodie and got on the bus to visit his girlfriend, texting her at 7:15 p.m. that he’d arrived.

Fifteen minutes later, police were called to the 3900 block of Poplar Street and found Marks with multiple gunshot wounds. His father, Jermaine Thurman, said his son had stepped into gang territory, where groups of young men on both sides of Girard Avenue have traded gunfire.

“They just decided to pick a target that was on the wrong side of the tracks,” Thurman said Wednesday morning at his home, where a Class of 2021 banner hung over a bed of red lilies reading “Congrats Nasir! We are so proud of you!”

The investigation is ongoing, police said.

A half an hour after Marks was shot in West Philadelphia, 15-year-old Kanye Pittman, of North Philadelphia, was fatally shot on the 2500 block of North Sydenham Street. He was a freshman at Benjamin Franklin High School, a School District spokesperson said.

The teen had been standing on a corner three blocks from home Tuesday night when multiple gunmen approached through a trash-filled, overgrown lot, firing nearly 30 shots, police sources said. On Wednesday, two dozen chalk circles marked the patches of pavement where police recovered ballistic evidence. No one answered the door at Pittman’s home. Detectives, parked near the scene, did not answer questions.

Authorities are also probing the shooting of a 16-year-old just before midnight on the 3800 block of North Sixth Street. The teenager, whom police did not identify, was taken to Temple University Hospital and is in stable condition.

The young people shot Tuesday night are the latest victims in a surge of unrelenting gun violence in the city. According to police statistics, 208 people have been killed this year to date, a 41% increase over this point last year, which saw more homicides than any year since 1990.

Of those homicide victims this year, 24 were under the age of 18, triple the number of children killed compared with the same time last year. So far, 827 people have been shot this year, and 10% of them were under 18. Last week, 16-year-old Quamir Mitchell, who was set to graduate from West Philadelphia High School, was gunned down at a playground.

Shootings spiked across the country in 2020, and some experts have blamed social disruption, saying it drove higher rates of violence. Among cities with more than one million residents, Philadelphia had the highest rates of both murder and nonfatal shootings between January and April, according to data compiled by researchers at Princeton University.

In Philadelphia this year, arguments are the most common cause of homicides in which a motive is known, according to police. To date, 63 people have been killed as a result of an argument, 30 because of a drug-related dispute, and 20 were the result of domestic violence.

“As disturbing as it is to see our victims becoming younger and younger,” Police Commissioner Danielle Outlaw said Wednesday, “it is also equally disturbing that we’re seeing our shooters becoming younger than ever as well.”

The pandemic exacerbated existing tension among young men, some of whom carry guns for protection and use them too frequently when disputes arise, said S. Archye Leacock, executive director of the Institute for the Development of African-American Youth Inc., a North Philadelphia-based mentorship program.

Leacock said now that the pandemic is more under control, city officials should invest more in neighborhoods that have underfunded schools and public spaces to empower young men to feel more positive about their surroundings.

“Many of these young people start off in difficult circumstances,” he said. “Then you impose all this crime and poor schools and dilapidated neighborhoods, and they are asked to make sophisticated, educated decisions. And they don’t have it.”

In West Philadelphia, Marks’ parents on Wednesday remembered their son as quiet and happy, one who shied from confrontation. He was a lefty who played first base, shortstop, and pitcher on the Overbrook baseball team — or “anywhere where the coach needed him,” his father said. He had recently enrolled in the University of Pennsylvania’s Upward Bound college preparatory program, his parents said. He had a job at a cleaning company.

“He was a good kid,” said his mother, Tenise Marks, breaking down in tears and clutching her son’s graduation photos. “He didn’t deserve this.”