61% of bankruptcies due to medical bills, 75% of them had insurance. What's the point of health insurance?

From my Apple Dictionary: 
catastrophe |kəˈtastrəfē|
noun
an event causing great and often sudden damage or suffering; a disaster

From Wikipedia:

Health insurance
Health insurance is insurance that pays for medical expenses. ...the covered groups or individuals pay premiums or taxes to help protect themselves from high or unexpected healthcare expenses. [emphasis added]

Most would agree that a core concept of health insurance is financial protection in the face of medical catastrophe.

From a recent study we learn that "[a]s recently as 1981, only 8% of families filing for bankruptcy did so in the aftermath of a serious medical problem."
Himmelstein et al.  Medical Bankruptcy in the United States 2007.  American Journal of Medicine Online June 2009

In 2007, prior to the economic 'downturn,' the study found that serious medical problems account for 62.1% of family bankruptcies. 

That's stunning enough, but the real shocker is that more than 75% of those people had health insurance when they filed for bankruptcy.

Link to a NYTimes article on the issue. (the article has a link to a pdf of the study)

What is it we really need in the US: health insurance or health care?  It sure doesn't seem like these two things mean the same.