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 broth. 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.