General Motors suffered from "incompetence and neglect" in dealing with a long-running ignition-switch defect in vehicles linked to at least 13 deaths, CEO Mary Barra said today.

The GM CEO also announced the creation of a fund to compensate victims. 

Barra said 15 employees found to have "acted inappropriately" have been fired. She did not name individuals. 

Speaking at the company's technical centre in Michigan, Barra addressed an estimated crowd of nearly 1,000 employees.

The largest US car maker unveiled the findings of an internal investigation into why it took more than a decade to finally recall vehicles with the safety defect. 

While Barra noted a pattern of "incompetence and neglect" that she blamed on "individuals" who failed to "disclose critical pieces of information" about the ignition switches, she added that there was "no conspiracy by the corporation to cover up facts." 

She said the internal investigation "found no evidence that any employee made a trade-off between safety and cost" in failing to deal with the safety problem. 

With the release of GM's internal investigation, US Congress is expected to announce a new round of hearings soon.

In the coming weeks, the company also might address whether it will establish a mechanism for compensating victims and their families. 

But the internal probe found senior executives were not to blame for a delayed vehicle recall involving the defective ignition switches, a person familiar with the matter said today. 

The source confirmed that the report concluded that Barra, executives who reported directly to her, the board of directors and former CEO Dan Akerson did not know about the defective switches before December. Barra has only been in the post for a few months. 

It also found that GM's general counsel, Michael Millikin, was not responsible for the mishandling of defects and the recall delay, the source said. Millikin, who led the internal probe with former US prosecutor Anton Valukas, is expected to continue working at GM.