BOSTON -- There were new calls Friday for a closer look into how the Department of Social Services handled the case of the family involved in last weekend's fatal fire in South Boston.

NewsCenter 5's Jorge Quiroga reported that two of the children were not supposed to be in the home. One of them died along with her 2-year-old sister.

VIDEO: Investigation Into Fire Continues

The home where Acia Johnson, 14, and her 2-year-old sister, Sophia, died had been visited by DSS several times since February.

"This is a family that's grieving. We are all grieving. For everybody, we all have a past. Everybody has a past. Nobody is perfect," family friend Justine Hathaway said.

There have been 11 complaints of abuse and neglect against the children's mother, Anna Reisopoloulos. Mayor Tom Menino said that there needs to be more case workers to make sure kids don't fall through the cracks.

"I think there are a lot of hardworking people at DSS, but there are too many cases they have to handle. Someone has to step up and help those folks who work there to do their job," Menino said.

Among the more recent DSS investigations, in June 2006, then 7-month-old Sophia swallowed prescription anti-depressant pills and had to be rushed to the hospital. In February 2008, Sophia was found wandering in the street when her older brother fell asleep while baby-sitting. In March, officials said that the mother threatened the same boy with a knife.

"DSS is examining the record to try to get a full sense of the facts," Gov. Deval Patrick said.

There are also questions about why the girls were still in their mother's home despite a long trail of complaints against her.

"When an extended family member has guardianship it is not unusual for children to be connected to and visit their biological parents. Once a guardianship is finalized, the guardian is the legal caretaker and responsible for decision making on behalf of the children," a DSS spokesman said.

"They make a decision to go live with the grandmother, but how often can they check to see if that child is with the grandmother or the elder in the family?" Menino said.

Meanwhile, officials are looking into whether the fire was deliberately set.