Shingles that have been blown off or become dislodged indicate that the roofing shingles have lost their tinsel strength and the sealant is no longer bonding them together which makes them very susceptible to damage from wind.
Occasionally, individual shingles can be replaced pending on how brittle the shingles have become with age. Generally, missing roofing shingles means that the shingle is in a greatly deteriorated condition and the end of the road is near.
