The Arcadia Police Department is investigating a fire that killed three children inside a home Saturday.
Police have arrested Marian Williams, charging her with three counts of first-degree murder, two counts of attempted second-degree murder, and arson.
Investigators say Williams set fire to a home on South Lee Avenue, killing Marcus Clark, 10, Kiani Clark, 8, and Kemaren Clark, 4.
Two adults, including the children's grandfather were also inside the home at the time. The grandfather is in serious condition, while the other person got out of the home without injuries.
Williams is the ex-girlfriend of the grandfather.
The Desoto County Sheriff's Office says Williams was arrested Friday morning for breaking into the same house and jumping on the grandfather and fighting him. She bonded out of jail at 12:30 on Friday afternoon.
The WFTS webteam contributed to this report.