AUSTIN, Texas (AP) Texas power grid manager was fired Wednesday amid growing calls for his ouster following Februarys deadly blackouts that left millions of people without electricity and heat for days in subfreezing temperatures.

Bill Magness, CEO of the Electric Reliability Council of Texas, becomes the second senior official to depart in the wake of the one of the worst blackouts in U.S. history. The states top utility regulator resigned Monday.

Magness was given a two-month termination notice by ERCOTs board in a meeting Wednesday night. The move came as the grid operator is now under investigation by the House Oversight Committee.

During this transition period, Bill will continue to serve as President and CEO and work with state leaders and regulators on potential reforms to ERCOT, the organization said in a statement.