A contractor is building a Hospital . All progress payments are being made on time and there is no breach on the part of the owner. During the construction the contractor finds that the land the project is being built is not zoned for a hospital . How may the contractor stop work on the project without being in a breach of contract ?

A contractor is building a Hospital . All progress payments are being made on time and there is no breach on the part of the owner. During the construction the contractor finds that the land the project is being built is not zoned for a hospital . How may the contractor stop work on the project without being in a breach of contract ?