The smell of bleach hung in the North Philadelphia air as a 40-year-old woman poured cleaning fluid and water over a dark purple bloodstain on the sidewalk and began scrubbing it with a plastic broom.

"I need more water!" she shouted, prompting a young boy to emerge from the house on the 2100 block of North Fourth Street with a fresh container of water. "I'm not going to stop until I don't see it no more."

The woman identified herself only as "Tank." She was scrubbing the sidewalk Tuesday in front of her sister's house, where she heard that a shooting had happened overnight and had rushed there from her home in another part of North Philadelphia.

A 14-year-old boy was killed, and three other boys and a man were wounded, officials said.

Capt. John Ryan of the Philadelphia Police Homicide Unit said the 14-year-old was shot in the forehead when two people took up positions on opposite sides of the block, near Susquehanna Avenue, just before midnight Monday and opened fire. At least 21 shots were fired, he said.

"They were clearly acting in concert," Ryan added. The four youths live within a block of the crime scene and apparently were the intended targets. "It's probably related to some neighborhood dispute, as it often is with kids this young," Ryan said.

The 14-year-old died about 5:50 a.m. Tuesday after surgery at St. Christopher's Hospital for Children, police said. Friends and relatives of the victims who gathered Tuesday afternoon at the shooting site identified him as Tyree Bates, of the 2100 block of North Fifth Street.

One of those friends, Eric Reid, 16, said he was with Bates when gunfire erupted.

"We're laughing and playing around in front of the steps," Reid said, describing the scene. "We started hearing popping sounds" and thought they were fireworks.

Reid said he looked north toward the sounds and saw the two people, one on the sidewalk and one in the street, firing in his direction. His friends started running.

"I turned around and my friend [Tyree] was on the ground with a bullet in his head," Reid said. "They shot, and then they just ran." He was not wounded.

>> READ MORE: 14-year-old killed, 3 other boys, man wounded in North Philadelphia shooting

Police said the other wounded boys were another 14-year-old and a 15-year-old, both of whom were in stable condition at St. Christopher's with wounds to the right calf and foot, respectively, and an 11-year-old who was taken by private vehicle to Hahnemann University Hospital. He also was in stable condition, with gunshot wounds to the hip and buttock.

Ryan said a 24-year-old man who was "downrange" from the shooting was hit in the stomach and did not appear to be a target. He was in stable condition at Temple University Hospital, police said.

"Our hearts go out to the families," Ryan said. "It's a terrible tragedy."

Bullets also slammed into two vehicles on the street. The four surviving victims were speaking to detectives, and witnesses also were being helpful, Ryan said.

Tyyon Bates said he was at home late Monday when he got a call that his brother had been shot.

At first, he said, he thought it was a joke — but then he saw others running to the scene and he ran after them.

"I seen my brother on the ground in a puddle of blood," said Tyyon Bates, who on Monday celebrated his 14th birthday.

Tyree, who would have turned 15 on Aug. 5, was "funny, goofy, talented," his younger brother said.

"He would always talk about his goals," aspiring to become a professional basketball player. "He was doing things that were keeping him out of trouble."

Tyree had just completed his freshman year at Kensington High School, said 15-year-old classmate Elias Santiago.

"He was just a good kid and a good friend," Santiago said.

The hours following the shooting followed a familiar pattern: People dealt with a bloody crime scene, others took to social media to express sadness and calls for action, and still others went to the scene to hold vigils, lay down candles and stuffed toys, and remember their dead friend.

Although no one in her family was injured in the shooting, Tank said, she worries that her 15-year-old son could become a victim of gun violence.

"It's tragic, but what are we going to do?" she said, pausing from her chore of washing away blood. "We can't protect our children from anything, and prayer ain't working, so what do we do? These were babies. It's hurtful. I been trying to stop crying, but it's hurtful."

Shawn Banks, 48, who runs a community youth mentoring program called PhillyWood, said the teens who were shot are among those whom he has mentored and coached in basketball.

"They're all good kids," Banks said, standing several feet from a white circle marking where one shell casing was recovered by police.

Of the youth who died, he said: "Don't just have another black kid die in vain. He was somebody's son, he was a good kid, he just graduated. He was a good boy who always listened to me."

The Rev. Adan Mairena of West Kensington Ministry, a church around the corner from the shooting scene, said some of the victims and their relatives are members of his church. The 24-year-old victim is a carpenter and union member who works hard to provide for his family.

"To hear that a 14-year-old got shot, and he's dead, it's hard to take in," Mairena said. "It just tells a lot about the times we live in and the society we're in, and the gun violence issue and who has access to guns and who doesn't and legislation that is not being passed in Harrisburg."

Across the city, 80 people have been shot this month, 16 of whom were killed, according to the city's open database.