Ride-hailing company Uber has hired former United States Attorney General Eric Holder to conduct an “independent review” of sexual harassment allegations made by a former engineer at the company. In an email to company employees, Uber Chief Executive Officer Travis Kalanick said it had been a “tough 24 hours” for the company, The Guardian reported. On Sunday, Susan Fowler had published a blog post claiming she had faced sexism and harassment at the company.

In the email, Kalanick said women made up only 15% of the workforce on the company’s engineering, product management and scientist teams. The revelation appeared to support Fowler’s claim that the percentage of women at her organisation at the company had dropped from 25% to 6% during her tenure there. However, the email did not provide statistics on the number of women in senior roles.

Kalanick said it was his “number one priority” for the company to make the company a “better organisation where we live our values and fight for and support those who experience injustice”. The company is also conducting an internal investigation led by its chief human resources officer, Liane Hornsey. Company board member Arianna Huffington and general counsel Angela Padilla will assist in that investigation. Kalanick said he and Hornsey would also publish a “broader diversity report” in the coming months.

In her post, Fowler said her first manager sent her messages saying that “he was looking for women to have sex with”. “When I reported the situation, I was told by both HR and upper management that even though this was clearly sexual harassment and he was propositioning me, it was this man’s first offense, and that they wouldn’t feel comfortable giving him anything other than a warning and a stern talking-to,” she had said. The former employee also detailed other incidents at the company, including sexist behaviour by HR department employees as well as team managers.

Her claims have once against brought the issue of discrimination by Silicon Valley companies and their users. In July 2016, house-sharing startup Airbnb hired Holder to investigate claims that homeowners were refusing to rent their residences to African-American guests.