The powerful Senate Finance Committee has written to all 50 governors, launching a wide-ranging examination of how America's foster care system has been outsourced to a vast web of for-profit companies and charities.

Committee Chairman Sen. Orrin Hatch (R-Utah) and ranking member Sen. Ron Wyden (D-Oregon) sent the 50 letters on Friday, seeking the names of all private foster care providers, state inspection and accreditation practices, financial information, and child abuse rates.

The Senate review was prompted largely by a BuzzFeed News investigation into cases of violent deaths and sex abuse at homes run by National Mentor Holdings, the nation's biggest for-profit foster care company. The reports examined how a National Mentor foster father molested his foster sons for over a decade while the company was supposed to be monitoring him. In another case, a National Mentor foster mother murdered her 2-year-old foster daughter, Alexandria Hill.

The company, which trades on the New York Stock Exchange under the name Civitas Solutions Inc., is paid by states and local governments to run foster care systems. Last month, as BuzzFeed News reported, the firm pulled out of Illinois, in the wake of an inspector general report alleging the firm had a "culture of incompetence."

Mentor has said that while there have been problems in the past, it has improved and overall provides quality foster care services in Illinois and across the country.

In their letter to state governors, Senators Hatch and Wyden cited "a particularly troubling series from BuzzFeed News reporting on the practices of a national private foster care provider network."

The effort by the Finance Committee could bring transformation and transparency to a low-profile but often profitable industry that controls the lives of hundreds of thousands of vulnerable children.