The cracks in the foundation of a Chicago nursing- home business began to appear almost immediately.

The owners stopped making mortgage payments on their crown jewel, the Rosewood Care Centers, barely a year after buying it in 2013. Paperwork about the chain’s finances was never filed with the government. Some money meant for the 13 nursing homes and assisted-living facilities went to prop up another investment.

In the end, the business defaulted last year on $146 million in government-backed mortgages — the biggest collapse in the history of a little-known loan-guarantee program run by the Department of Housing and Urban Development.

The Rosewood debacle demonstrates the problems plaguing the HUD program, which helps nursing homes obtain affordable loans and has become a linchpin of the American elder-care system.

By the government’s own admission, the federal agency’s stewardship of the program has been haphazard. Its oversight of nursing homes has been weak. When HUD officials have spotted problems, they often have been slow to respond. Sometimes it has taken years to intervene, allowing the finances at certain facilities to unravel to such an extent that the quality of care was undermined.