The new health insurance marketplace Healthcare.gov went down again this morning, the latest hiccup in a month of technical problems. The timing could not have been worse for the administration: Health and Human Services secretary Kathleen Sebelius was in the middle of testifying before Congress.

"Let's put the screenshot up,"  Representative Marsha Blackburn (R-TN) said, referring to an image of the error message on Healthcare.gov today that reads, "The system is down at the moment."

"This is what is happening right now with the website," Blackburn said. "We've had somebody in the back trying to sign on. It is down. It is not working."

The error is the result of a problem in a data center operated by Verizon's Terremark, Sebelius says. The data center failed over the weekend, putting Healthcare.gov out of service for several hours.

The administration announced Monday morning that the problem was resolved, but the site has continued to experience intermittent downtime. Verizon had an "additional problem" on Tuesday "and it continues on," Sebelius told Blackburn.

Healthcare.gov is the primary way for Americans to get health insurance, which is now a requirement under the Affordable Care Act (ACA). However, the site has had bugs and errors since its launch on October 1st, preventing many people from signing up. The administration has extended the law's deadlines for buying health insurance as a result.

Administration officials are now being held accountable for the glitchy website, an aspect of the law that was undeniably bungled.

Other complaints raised by Congress, including anecdotes about rising costs and cancelled plans, are easier to defend. The administration can say that average prices are lower even if some people are now paying more. And to the second point — that President Barack Obama said people could keep their insurance and now some have had their plans canceled — the administration can say that the law included a grandfather clause specifically so that insurance providers would not be required to cancel old plans. Some providers decided to cancel plans anyway, forcing some Americans to seek new insurance. But providers have always been able to cancel plans at a whim, Sebelius testified.

The website is a different story. The numerous glitches, which at first prevented people from even creating an account, made the site virtually unusable for tens of thousands, or possibly hundreds of thousands, of people.

The administration says the federal site has had more than 20 million visits, but only around 700,000 people have submitted applications through the federal and state marketplaces. The administration says it will not release the number of people who have successfully enrolled in plans through Healthcare.gov until mid-November.

At least one government contractor, QSSI, testified that the administration was warned that there were issues with the website weeks before launch. Sebelius testified that the administration spent about $118 million on the website itself and about $56 million on supportive infrastructure.

The White House is now in damage control, promising to fix the website by November 30th. So far, no one has been fired, but there have been calls for Sebelius's resignation. "Hold me accountable for the debacle," Sebelius said today in response to a question from Representative Blackburn. "I'm responsible."