Please help resolve the case study

Peter's Plants, Inc., specializes in growing Pink Tuberous Begonia flowers. Peter's enters into a contract to deliver 1,000 of its genetically modified pink begonias to Lester's Flowers for $5 a plant. Relying on the contract, Lester's enters into a second contract with a large apartment complex to plant 1,000 pink begonias around its property. A large ice storm demolishes all of Peter's begonia flowers. In turn, Peter's didn't meet its supply to Lester's, and Lester's didn't plant the flowers at the apartment complex. The apartment complex sues Lester's for breach of contract, and Peter's is brought as a cross-claim defendant. What are the arguments Lester's and Peter's should make in defense of not performing under their respective contracts?