When two bear cubs at Lake Tahoe Wildlife Care died in the fall, it touched off an extensive investigation into the cause, as well as sadness and shock for those associated with the local nonprofit.

Now roughly five months later, LTWC's four remaining cubs are healthy, and two of them are expected to be released back into the wild in the coming weeks.

The two cubs that died in the fall, Nevada and Filmore, ultimately succumbed to adenovirus, as the Tribune reported in October.

Since then, officials have confirmed that it was a canine form of adenovirus, according to LTWC.

Through additional testing, the remaining four cubs at LTWC proved to be positive for the virus. LTWC took immediate measures to "quarantine" the remaining cubs and the rest of the rehabilitation compound.

The four remaining cubs continued to show excellent health, according to LTWC, and are expected to remain healthy.

They bears entered into their hibernation period in early December and have been seen nestling in the straw inside their den.

The loss of the two bear cubs in the fall stimulated additional investigation by California Fish and Wildlife and pathologists at the California Animal Health and Food Safety (CAHFS) laboratory, according to LTWC. Their work has shown that other black bears in California have been exposed to canine adenovirus. The investigations are ongoing and the significance of these findings is not yet known.

The two cubs expected to be released sometime in late March or early April are Burns Canyon and Laytonville. The other two cubs from the Tahoe area (Sky and Bliss) are scheduled to be released in late April or early May.