"Unthinkable:" Grandfather's ex arrested after 3 children killed in fire at his home

ARCADIA, Florida -- Three children lost their lives in a house fire in Arcadia, Florida on Saturday, March 11th -- and police are calling the fire suspicious. A suspect is in custody.

"It's unthinkable, you know? I can't imagine what it would be like if my children died in a fire," a neighbor said.

Relatives said three boys, ages 10 and under, were spending time at their grandfather's home when the fire broke out. The call came in around 4:30 a.m. Saturday.

"I think it's just absolutely tragic," a neighbor said.

"We're trying to put all the pieces of the puzzle together right now. Only thing we know right now is we have three deceased bodies and were working on everything from there," a first responder said.

Arcadia police are calling the fire suspicious. 49-year-old Marian Evette Williams was taken into custody. Relatives said Williams is an ex-girlfriend of the grandfather who lived in the home.

"I think its tragic. I think it's almost incomprehensive that a human being could do something like that, knowing that there were occupants in the house," a neighbor said.

Her rap sheet shows Williams has a violent past, including a very recent incident. She was just arrested Friday, March 10th for battery and burglary, but bonded out that very same day.

Officials are now investigating how and why the tragedy on Saturday morning happened.

"Just very sad to hear that something, especially children, would die. It's, it's horrible," a neighbor said.