1) Heat the oil in a heavy large pot over medium heat. Add the garlic, bay leaf, and crushed red pepper. Saute until the garlic is tender, about 1 minute. Add the wine and bring to a boil. Add the tomatoes. Bring to a simmer. Simmer until the tomatoes begin to break down and the flavours blend, about 5 minutes. Stir in the clams. Cover and cook for 5 minutes. Stir in the mussels. Cover and cook until the clams and mussels open, about 5 minutes longer.
2) Using tongs, transfer the opened shellfish to serving bowls (discard any shellfish that do not open). Add the prawns and basil to the simmering tomato . Simmer until the prawns are just cooked through, about 1 1/2 minutes. Divide the prawns and tomato broth among the bowls. Serve with the warm bread.