Joseph Donnelly was parking his car behind William L. Sayre High School in West Philadelphia yesterday morning when he heard the first gunshot.

He flung open his car door and hurled himself to the ground. Immediately, a barrage of bullets chewed through the air just feet away as Donnelly tried to disappear into the pavement.

"There wasn't a chance to be scared," said Donnelly, construction manager of a $12 million renovation at the school. "It was just: 'How do I get closer to the ground?' "

When the gunfire subsided, one Sayre student lay bleeding and seriously wounded, while his attackers - who police believe were three other Sayre students - escaped on foot.

Detectives believe the shooting erupted from an ongoing territorial feud between neighborhood teens from 56th Street and others from 60th.

The 8:25 a.m. incident, which prompted a daylong lockdown at Sayre and at a nearby church-run day-care center, left some shaken school officials thanking fate for its timing.

"Just imagine if this had happened a half-hour earlier," said district chief executive Paul Vallas, referring to the 680-student school's 8 a.m. starting time. "It could have been a much more tragic situation."

The school parking lot, off 59th Street near Locust, was mostly empty when three teenagers confronted a Sayre sophomore and began blasting away.

"I heard . . . seven or eight gunshots," said John Ingram, 37, who lives around the corner from the school. "It sounded like a little baby cannon. It was loud, though, and it got me out of bed. I said: 'That was too close!' These young kids done got out of control."

Crime-scene workers later determined at least 11 shots had been fired, possibly from more than one gun. That number of bullets indicates the attack was "victim-specific; it's not a random act," said Capt. Michael J. Sinclair, commander of Southwest Detectives.

Although several video cameras mounted on the school pointed at the shooting scene, the cameras - part of an ongoing security upgrade - weren't yet wired or working, Vallas confirmed.

A silver 9 mm semi-automatic Ruger had been discarded next to a nearby utility pole, cocked and presumably loaded, Sinclair said.

Donnelly told police he had seen the 17-year-old victim pull a pistol from his waistband and hand it to a teenage girl, who fled with it. Detectives were trying yesterday to identify that girl.

Investigators planned to dust the abandoned gun for fingerprints and do gun-powder-residue tests on the victim to determine whether he had fired a weapon, Sinclair said.

The victim, identified by a police source as Tariq Hannibal, had surgery yesterday at Children's Hospital of Philadelphia for wounds to his leg and buttocks, Sinclair said. Detectives also were probing whether a Tuesday shooting was related to yesterday's violence.

In that case, a 19-year-old man showed up at a local hospital with gunshot wounds. He told police he had been shot in Sayre's schoolyard about 4:30 p.m. While Sayre security officers confirmed they'd heard gunshots, city police found no evidence to pinpoint the shooting scene, Sinclair said.

Joseph Golden, the district's chief safety executive, lamented yesterday's violence as another "disturbing example of the pervasiveness of gun violence in the city."

Vallas used the incident to demand tighter gun laws.

"The joke around town is: Sometimes it's easier to get a gun than a book," Vallas said. "Clearly the [gun-control] laws need to be tougher."

Parents also play a pivotal role in ensuring students' safety, Vallas added.

"I always say: 'Feed and frisk.' Make sure the kids are fed when they get home from school, and make sure you frisk them on their way to school," Vallas said. "Parents have to take responsibility that when their kids are on their way to and from school, that they have the appropriate things with them."

So far this school year, from September to yesterday, 10 firearms have been found in or around schools, said district spokesman Fernando Gallard. He said seven weapons were found in schools, two on school property and one on the highway outside a school.

That number is up from six firearms found in or around schools in all of the 2005-06 school year, Gallard said, when three weapons were found in schools and three on school property.

School officials planned to send letters home to parents yesterday about the incident. They also beefed-up security for the day and crisis intervention teams were available to counsel frightened students, Golden said.

But one neighbor predicted that tightened security would do little to curb violence around Sayre.

"This is not unusual for this neighborhood," said Freida McClendon, a mother who sends her two teenagers to private schools because she feared for their safety at Sayre. "This is an everyday thing. They fighting all the time out here."

Overhead, a detective walked across the roof of her rowhouse and five others, hunting for any gun-cartridge casings that might have landed there during the gunbattle.

Before she shut and locked her door on the crime scene outside, McClendon said: "I'll have to get barbed wire on my fence now." *