(KDKA/CBS) — The confirmed death count from Friday’s devastating tornado outbreak rose significantly Monday.

Kentucky Gov. Andy Beshear announced at least 64 people were killed in his state, which he said suffered “the worst tornado event” in its history.

Beshear said it may take weeks before the final toll would be known. Dozens of people remain unaccounted for. The severe weather and tornadoes affected seven other states, killing at least 12 additional people.

CBS News and CBSNews.com have crews in Kentucky covering the aftermath of the tornado outbreak. Click here for updated information.