What resources/ideas would you suggest to determine why the sassafras tree in my yard died. It was planted in 2014 at approx 40" tall and last fall was about 19-20' tall. It had normal green leaves during the summer, normal fall color, and seems like it had buds formed but no leaves have appeared this spring.. The only life visible currently is there are some sprouts from the base of the trunk. The attached pictures are saved as jpeg from a powerpoint presentation -- I can send the actual photos also. The one shows planting and how it looked last fall (green will a little flagging from the cicadas and in fall color). The others are from May of this year. Thank you