PROVIDENCE –– The injuries that killed 3-year-old Thomas “T.J.” Wright were inflicted when his foster mother came home from a night out 3½ years ago and found a mess on the living room floor, the baby sitter in the Katherine Bunnell murder case testified yesterday.

“Why did you mess up my house? Why did you mess up my [expletive] house?” Kayla Roderick said Bunnell demanded as she dragged T.J. out of bed and led him around the living room of her Woonsocket apartment.

“Why did you do that to my floor? Why did you mess up my living room?’” Roderick said Bunnell said.

“She was very angry and she was saying it very loud,” Roderick testified.

“She started hitting him. She hit him in the chest and in the back.”

She testified in Superior Court, where Bunnell, 24, is being tried on charges of murder and conspiracy to murder.

Prosecutors say Bunnell and her boyfriend at the time, 27-year-old Gilbert Delestre, beat T.J. so badly that he suffered broken bones, bruises and head injuries so severe his brain shifted inside the skull.

The mayhem broke out around 2 a.m. Oct. 30, 2004, after the couple arrived home and Delestre pointed out a tipped-over bowl with yogurt and milk on the floor.

Roderick was there to baby-sit Bunnell’s daughters, Destiny, 7, and Daziya, 5, and her nephews, David, 10, Mickey, 6, and T.J. Wright.

Bunnell, who became the boys’ foster mother when her sister went to prison in Illinois for drug possession, promised to be home by 11 or 11:30 p.m., so Roderick, who was 15 at the time, could get up at 6 a.m. to play in the high school band.

But midnight passed and Bunnell didn’t return. Roderick telephoned her mother to say she was going to be late.

She lay down on the living room floor after making a bed on the sofa for T.J., who had come downstairs because he couldn’t sleep.

“He was energetic,” Roderick testified. “He liked to jump around.”

By the time Bunnell and Delestre came home, T.J. was back upstairs, asleep with his brothers. Bunnell looked at the mess on the floor and she demanded to know who had done it. “I said that T.J. might have done it,” Roderick testified, “because he had gotten into the toothpaste that night.”

Delestre went upstairs and entered the boys’ bedroom. Roderick said she heard three or four loud slaps, then T.J. crying.

“Those were ‘I’m very upset. I’m going to hurt you’ slaps,” she said in response to a question from Gerard H. Donley, Bunnell’s defense lawyer, who is trying to convince the jury that Delestre inflicted the fatal injuries.

Delestre, who, like Bunnell, is being held without bail at the Adult Correctional Institutions, will be tried separately.

To counter the defense strategy, Assistant Attorney General Stacey P. Veroni got Roderick to testify in excruciating detail about the beating Bunnell administered.

Roderick testified Bunnell held the 32-pound toddler by the arms as she carried him downstairs from his second-floor bedroom, letting him fall face first onto the floor when they reached the foot of the stairs.

She said Bunnell hit T.J. in the back and the chest as she dragged him across the living room, grabbing him by the wrist and pulling him to his feet every time he fell.

Bunnell yanked T.J. over to the spot where he had poured milk and yogurt into a bowl, and slapped him in the face four times –– twice with her palm and twice with the back of her hand, Roderick testified.

Then, Roderick said, Bunnell got milk from the kitchen and poured it on T.J., emptying the container on his head.

“She asked me if I wanted to go home and I said, ‘Yeah,’ because it was late and I had to get up in three or four hours,” Roderick testified.

“She said, ‘Where are my [car] keys? I want to [expletive] take her home.’ ”

At that point, Roderick was distracted by the sound of someone throwing up outside the apartment. She looked out and saw Delestre’s cousin, Jose Santiago, vomiting in the parking lot.

By the time she turned back around, T.J. was flying through the air, Roderick testified. Delestre had picked up the toddler and tossed him across the living room, causing him to land with his left leg twisted under his belly, she said.

Veroni asked Roderick why she didn’t try to stop the beating.

“Because I was afraid of Katherine and Gilbert,” a visibly upset Roderick responded. “Because I had never seen anybody hit a kid like that, and that was family, so if she did that to him, I was afraid of what she was going to do to me.”

jcastell@projo.com