SACRAMENTO, Calif. (AP) — California's high-speed rail project has lost a top leader without a replacement on tap. Chief Operating Officer Joe Hedges' Monday departure injects fresh uncertainty into a project constantly in flux.

Rail spokeswoman Melissa Figueroa gave no details on Hedges' departure and he could not be reached for comment. His exit came the same day rail board Chairman Tom Richards announced the conclusion of an investigation into personnel matters and fraud allegations. He says no fraud was found.

California's plan to build a high-speed rail line between Los Angeles and San Francisco has long faced cost overruns, delays, and leadership shakeups.