Embattled Massachusetts Department of Children and Families Commissioner Olga Roche  has resigned under mounting pressure following the deaths of three children.


The move Tuesday comes after calls from top Democratic lawmakers _ including Massachusetts House Speaker Robert DeLeo and Senate President Therese Murray _ for Roche to be replaced as head of the child welfare agency.


Authorities say the family of a 2-week old Fitchburg baby who died over the weekend was being monitored by state child welfare officials.


In the second case, a DCF spokeswoman says a fax from Grafton police about possible harm to a 4-week-old who later died was misplaced for six days.


The body of a third child, 5-year-old Jeremiah Oliver of Fitchburg, was found off a highway this month. Jeremiah's family was also under DCF supervision.