The candidates running for Massachusetts governor toughened their rhetoric during their first Boston televised debate with Republican Charlie Baker and Democrat Martha Coakley jousting on questions of how best to overhaul the state's child welfare agency and bring down health care costs.

Coakley again criticized an ad by a pro-Baker super PAC that claimed she opposed reforms in the Department of Children and Families. Baker said no one was questioning Coakley's work as a child advocate, but he faulted her for fighting a lawsuit that sought to make changes to the agency.

Coakley also criticized Baker's rising salary when he was CEO of Harvard Pilgrim Health Care. Baker said he helped stabilize the health care giant's finances and didn't spend a lot of time negotiating his salary.

Independent candidates Evan Falchuk, Scott Lively, and Jeff McCormick also participated.