Representatives of the state’s Department of Public Utilities held a public hearing in the Massasoit Conference Center Tuesday night. In September, the Quincy City Council voted to force the DPU to investigate the response of National Grid to tropical storm Irene. That decision caused the agency to hold four public hearings across the state. Three dozen people attended the hearing, including elected officials, fire chiefs and representatives of National Grid. Marcy Reed, President of National Grid Massachusetts, said competition for repair crews among utility companies all along the east coast limited her corporation to half the number of crews it needed. State Sen. Thomas Kennedy said Reed’s report reminded him of his school report cards – lack of effort. A parade of fire chiefs said they kept up-to-date power restoration priority lists with National Grid which the corporation ignored. They said repeated requests to determine whether downed lines carried electricity or could be safely moved to allow removal of downed trees, received no response for three or more days. A representative of the Attorney General’s office said she would work with DPU in investigating the corporation’s response.