A senior state manager who oversaw most of the development of Oregon's struggling health insurance exchange resigned Thursday as developers continue trying to find some way get the online enrollment system to work.

Carolyn Lawson stepped down as chief information officer of the Oregon Health Authority and the Department of Human Services for "personal reasons," the agencies' leaders wrote in a terse memo to Lawson's staff and other senior officials.

"I have recently experienced a family loss which has caused me to reevaluate many things in my life including continuing to commute to Oregon while my family is in California," Lawson wrote in her resignation email. She described the decision as "a highly personal choice" and said she hoped it would not negatively impact the agencies.

Attempts to reach Lawson through her state-issued cellphone and email account were unsuccessful. In previous interviews, Lawson has staunchly defended her agency's work.

Oregon leaders bragged for two years that it would have one of the nation's most advanced insurance marketplaces, but they were embarrassed when the online enrollment site wasn't ready to launch on schedule in October. It still doesn't work nearly three months later.

The exchange has had to rely exclusively on paper applications, and it hired or reassigned more than 400 workers to process them manually. Oregon has been the slowest state to enroll people in private insurance, though the pace has picked up significantly in the past two weeks.

Lawson came under fire a year ago when state lawmakers accused her of misleading them about available technologies. More recently, technology experts and her own boss have laid blame for the problem with her decision to have the state act as the project's systems integrator, a sort of general contractor to oversee the complex integration of disparate parts of multiple vendors.

Lawson was hired in 2011 to oversee technology projects for the two state agencies that administer health and human services programs. The state had just approved creating a health insurance exchange, and it was tacked onto a separate project to modernize the internal computer systems for both agencies.

Lawson was responsible for delivering the technology on a very tight schedule.

The $48 million federal grant funding Lawson's work ran out unexpectedly in May. The development work was hastily handed over to staff at Cover Oregon, a semi-autonomous state agency created to run the exchange business using Lawson's technology.

Shortly after taking over, a Cover Oregon official wrote a scathing report highlighting serious problems with its functionality.

Before coming to Oregon, Lawson held IT positions in several California state agencies. Oregon paid her just under $179,000.

Lawson's deputy, Steve Powell, was named interim chief information officer.

"We want to thank Carolyn for her service to our agencies and the state," OHA Acting Director Tina Edlund and DHS Director Erinn Kelley-Siel wrote in their memo.

Lawson is the second senior official to step aside amid growing frustration with the technology problems. Cover Oregon Executive Director Rocky King took medical leave, and the agency's board created a search committee to find a replacement. It's not clear if or when King will return.