TULSA, Oklahoma - A 9-month-old boy remains in critical condition after police said his mother's boyfriend shook him Tuesday.

Comorion Marshall's mother, Chelsey, said DHS won't let her see him and placed her two other children in protective custody.

Comorion was born last July - Chelsey said he was a happy, healthy baby.

"He was always a smileful, playful baby. He never cries unless he's hungry. Don't understand why he would hurt such an innocent child," she said.

Chelsey said she went to work Tuesday at 4:30 a.m. and left Comorion, his 2-year old brother and 5-year old sister with her live-in boyfriend, Ganey Fairley. She said they lived together only a month but had known each other about four years.

Chelsey said she called during the day and he said everything was fine, but when she got home that was not the case.

“He was just standing there like this, you know, saying ‘your baby's unresponsive, your baby's unresponsive.’ He was like, ‘I was going to call you.’ Why didn't you call the ambulance," she said.

Chelsey said Fairly told her he tripped and fell with the baby, shook the baby to revive him, then put cold water on his face and waited for her to get home.

He's been arrested.

"I've seen him act violent to another female but I thought that was their thing. He's always been so sweet and generous around me. I never expected this, you know," Chelsey said.

She said Fairley has two kids of his own and has watched her children before with no issues. She said daycare didn't open until 6 a.m. and she didn't have time to take the kids there during her 30-minute lunch hour.

"If I could go back in time, I wouldn't have cared about that lunch break," Chelsey said.

She said Comorion is in very critical condition and doctors tell her the next few days are crucial.

They said he only has a 50 percent chance of survival, and if he does live, his life could be changed forever.