YVONNE HILLER didn't like LaTonya Brown and Tanya Wilson.

The three worked in the third-floor mixing room at the Kraft Foods plant on Roosevelt Boulevard near Byberry Road in Northeast Philadelphia. Hiller had fought with Brown and Wilson - verbally and physically - for at least two years, accusing them of throwing chemicals at her and talking behind her back.

Thursday night was the latest fight. It led to Hiller's supervisor booting her out of the plant with a suspension. But Hiller refused to go quietly, police said.

The 43-year-old Crescentville woman went to her car, where she kept a .357-caliber Magnum handgun. She returned, pointed it at two unarmed security guards and demanded re-entry, police said.

She then beelined to the third floor, where she found Brown, 36, Wilson, 47, and two other co-workers in a break room.

She instructed one to leave, saying she had no quarrel with her. Then, according to police, she began blasting away.

She allegedly shot Brown once in the head at close range and Wilson in the side. And she allegedly shot Bryant Dalton, 39, who'd also been involved in the earlier argument, in the neck.

She then hunted down her supervisor in a third-floor hallway and allegedly fired at him but missed.

She also allegedly fired at and missed a heroic Kraft mechanic who followed Hiller, shouting at co-workers to flee and reporting her movements on a cell phone to a 9-1-1 operator and on his walkie-talkie to other employees.

She also fired once at the first officers on the scene, Homicide Capt. James Clark said.

Hiller then hid in a darkened, second-floor office and called 9-1-1, unaware that seven co-workers had cowered in fear in an adjoining room.

" 'I'm the person you're looking for at the Kraft Nabisco building,' " Hiller said to a dispatcher, according to Cpl. Janice Leader.

Leader, a 9-1-1 supervisor, then got on the phone. " 'So, now you want to help me?' " an agitated Hiller said, according to Leader. " 'Now you want to help me?' "

Leader said she spent about 40 minutes on the phone and told Hiller that police were on their way to the room. "I told her, 'Put the gun down. Put the gun down. And put your hands on top of your head so they'll know you're not being aggressive to them,' " Leader said.

SWAT officers stormed the building, apprehended Hiller and freed the hiding co-workers at 9:36 p.m., about 40 minutes after the shooting rampage began.

Paramedics declared Brown, of Poplar Street near 11th in North Philly, and Wilson, of 10th Street near Erie Avenue in Hunting Park, dead at the scene. Dalton was in good condition last night at Thomas Jefferson University Hospital.

Hiller, who didn't have a criminal record and lived by herself in a two-story brick rowhouse with a tidy lawn and porch on Carver Street near Tabor Avenue, is being held without bail on murder and related charges. Neighbors said she has a son in his 20s.

Some neighbors described her as a hypochondriac who worried about a smell in her house and often called 9-1-1. She had a security camera mounted outside.

Hiller, a 15-year Kraft employee, who had worked in the mixing room for six years, allegedly also complained to the Occupational Safety and Health Administration about her work. An OSHA form, dated Nov. 23, 2009, said a Kraft Foods employee complained about "being harassed by various other employees working in the same area" and alleged "being sprayed with chemicals and even deer urine" at work.

Kraft, in a Dec. 3, 2009, letter to OSHA, said it had received complaints by a mixing-room employee alleging "exposure to a variety of chemicals." The company said it had offered to test the employee's clothing and offered "additional medical review," but she refused. It said it did not find evidence of the employee's claims.

A Kraft spokeswoman said by e-mail last night that Hiller later claimed she made the anonymous complaint.

Next-door neighbors of Hiller yesterday described a time when she threatened violence. Dierr Rowland, 12, recalled playing his radio loudly one afternoon last year. Hiller came to his home "screaming at us," the boy said.

Tonine Rowland, 35, Dierr's mother, said after she and a friend argued with Hiller, Hiller tried to get into her home, and Rowland's friend kicked open the screen door, hitting Hiller. Hiller returned with a metal bat and banged on the screen door.

"Bitch, come out," Hiller yelled to Rowland's friend, Rowland said. Hiller returned home and called 9-1-1, but the police who responded didn't issue any citations, Rowland said.

"I think they were really tired of her. She would just call the police randomly, same as the Fire Department," Rowland said. "She would say she just smelled smoke."

Rowland said Hiller "was always angry" and "would always seem stressed" and was a "hypochondriac." Referring to Hiller's security camera, Rowland said Hiller "swore the neighbors let their dogs pee" on her front lawn.

Another neighbor, 45, recalled how Hiller was always worried about a smell in her house. The woman, who did not want to give her name, said she went to Hiller's "so clean, so immaculate" house three years ago and smelled something, but didn't know what it was. Hiller said she thought the smell was in her wall, this woman said.

Hiller complained that she was afraid some neighbors were "trying to hurt her," the woman said. "It got to the point where it started to scare me. Like something was wrong with her mentally."

George Harris, 45, said Hiller was a friendly person and he was "shocked" to hear of the shooting. Hiller expressed interest in purchasing a pup from his pregnant Presa Canario dog, he said. "I was telling her the dog's good protection for her home," he said.

Clark, the homicide captain, said Hiller legally owned her gun and had a permit to carry. When she went to get the gun Thursday night, she called a male friend to complain she'd had enough of the harassment and would shoot her tormentors. Her friend called 9-1-1, Clark said.

Meanwhile, Wilson's and Brown's families yesterday mourned their loved ones. "It was Kraft's fault LaTonya is dead," said Jenine Harris, Brown's best friend. "There was a history of problems with this lady."

Brown's mother, Robin, said she spoke with her daughter about an hour before the shooting and her daughter told her she had a meeting with her supervisors regarding Hiller.

Robin said her daughter, who had four children, ages 6 to 22, told her: "I'm scared. I don't feel safe here."

Wilson's family was equally stunned by the tragedy.

"When a person is as sweet and kind as she was, you're always going to miss that," said Julia Norris, Wilson's mother-in-law. "What you have left are all the sweet memories. You just have to go by that."