Erin Moran’s husband is speaking out.

In an open letter to fans, posted on Scott Baio's Facebook page, Steve Fleischmann talked about his wife's cancer battle.

>> Read more trending news

Fleischmann said he first noticed signs of her cancer just before Thanksgiving, when she woke up with blood on her pillow.

He wrote:

"So we went to an ENT who said they wanted to biopsy it. It came back squamous cell carcinoma. She started radiation and chemo. Five days a week radiation and chemo only on Thursdays. We did that the whole time. It got so bad so fast. By the middle of February, Erin could no longer speak or eat or drink. She had a feeding tube implant and I feed her 6 to 8 times a day. She was still happy, she was active, she texted people on her phone all day."

Fleischmann continued:

"On the 21st she was having trouble breathing. She woke up on the 22nd, she was not 100%. She needed Kleenex, so i went to the store and came back. She was there watching T.V in bed. I laid down next to her held her right hand in my left. I feel asleep woke up about a hour later still holding her hand and she was gone, she was just gone."

He said he was not aware of the severity of her diagnosis until he talked to the coroner.

Related: ‘Happy Days’ actress Erin Moran dead at 56

“The coroner told me it was really, really bad. It had spread to her spleen, she had a lot of fluid in her lungs and part of her brain was infected. The coroner said even if she was in the hospital being pumped full of antibiotics, she still would not (have) made it. He said it was the best that she was with me and went in her sleep,” he wrote. “So that’s it.”

Related: 'Happy Days' stars share condolences after Erin Moran's death

Moran's "Happy Days" co-star, Anson Williams, was one for the few friends who knew about her cancer battle.

"It's hard to wrap your arms around it," Williams told People Monday. "She was having treatment for throat cancer, so I was contacting her husband and her, and she seemed to be fighting it, really doing well. I was just shocked when I got the call she had passed. I had no idea it was that bad."