Two powerful storm systems hit Knoxville one year ago this week.
The evening of June 21 is when the first storm struck.
The second system moved through in the early morning hours of June 24.
Hundreds of trees were blown down, houses damaged and roads were flooded during both weather events.
Tree companies were working non-stop into the fall months.
Cortese Tree Specialist said hidden damage is now appearing.
"Six months to eight months later, you find out they [trees] have a crack in the trunk or a crack in the upper canopy that was not a problem before. It could become a problem now if another storm comes along, or once it leaves out this year it may not be able to support the weight," said Sam Adams with Cortese Tree Specialist.
Last summer, many tree workers worked long hours to meet demand.