EAST ORANGE — It was an ambush. Bodies were strewn across a bloody floor, a witness said, young men and women trampled over one another to escape the gunfire, some of them even dived out of windows.

When it was all over shortly after midnight yesterday, two men and three women lay wounded, one mortally, in a rented house on South Clinton Street in East Orange, about a mile from Seton Hall University.

What had started as an off-campus party attended mostly by students ended with the death of Seton Hall sophomore Jessica Moore, 19, of Disputanta, Va.

Authorities did not identify the other victims, but they said in addition to Moore, two are Seton Hall students and one went to the New Jersey Institute of Technology. The fifth is from New York City.

Before the attack, an uninvited guest crashed the party, said East Orange Police Director Jose Cordero. When the man was confronted, a fight broke out. The man left but came back a short time later with a gun in his hand.

"The whole crowd was like a stampede. Girls were being trampled on ... it was pure terror," said a man who attended the party. He identified himself as a May graduate of Seton Hall who lives in Newark but did not want to give his name for fear of his safety.

When the shooting was over, Moore lay on the floor, the man said. But for the trickling blood, she appeared to be asleep.

Lying next to her was Nakeisha Vanterpool, 19, of the Bronx, who was cradled by her twin sister, Nicole, the women’s aunt said. Blood streamed from two bullet wounds in her arm and jaw.

"She can’t believe all this happened," said her aunt, Nina Vanterpool, of southern New Jersey. "I think she’s still in shock right now."

A suitemate of Moore’s, Vanterpool was being treated yesterday at University Hospital in Newark, where she communicated with friends and family on Facebook.

"This is the most unreal feeling I have ever felt (Jessica) is not only my friend but my sister life will never be the same," she wrote.

Another victim, Yvan Christophe, 25, was shot in the leg, said a man identifying himself as Christophe’s uncle at his nephew’s former East Orange residence. Christophe lists himself as a 2007 NJIT graduate on his Facebook page.

The suspect in the shootings was still at large late yesterday, authorities said. At a news conference yesterday afternoon, Cordero said the Essex County Prosecutor’s Office, along with the East Orange, South Orange and Newark police departments and Seton Hall’s campus police are involved in the search.

"We’ll leave no stone unturned until all those involved with this are brought to justice," said acting Essex County Prosecutor Robert Laurino.

Added East Orange Mayor Robert Bowser: "We will not tolerate this kind of violence. ... The shooter picked the wrong city. He will be apprehended."

A psychology major and an aspiring singer, Moore once wrote on her MySpace page that she wanted to work with military veterans who suffer from post-traumatic stress disorder.

"She was a smart, sweet girl," said Kendra Nickens, whose two daughters were close friends of Moore’s. "She loved playing basketball and softball."

Moore was a varsity athlete in both sports at Upper Merion Area High School in King of Prussia, Pa. The young woman had lived in a variety of places because her father was in the military.

"She was just a great kid," said John Whitney, who coached Moore in softball her junior and senior years at Upper Merion. "When Jess first came up she was very raw, but she had a lot of talent. She was a pleasure to coach."

Interim Seton Hall president Gabriel Esteban, himself a father of a student at the university, last night called the attack a "senseless tragedy."

"This is the phone call you really don’t want to get," he said.

Essex County Crime Stoppers is offering a $10,000 reward for information leading to the arrest and conviction of the person or people responsible for the slaying and attempted killings. Anyone with information about the crime, says the Essex County Sheriff’s Office, should contact the East Orange Violent Crimes Task Force at (973) 266-5060 or East Orange Anonymous Crime Tips Hotline at (973) 266-5041.

By Nyier Abdou and Amy Ellis Nutt / The Star-Ledger

Staff writers Megan DeMarco, Victoria St. Martin, David Giambusso and Julie O'Connor, as well as Eugene Paik of the New Jersey Local News Service, contributed to this report.

Previous coverage:

• Seton Hall student dies following shooting at off-campus party

• Five people are shot near off-campus Seton Hall University house