In a large pot of salted boiling water, cook the fettuccine according to package instructions until al dente. Drain and set aside, reserving 1 cup of pasta water.

Prepare the Seafood

In a large skillet, heat the olive oil over medium heat. Add the minced garlic and sauté until fragrant, about 1 minute. Add the scallops, mussels, clams, and shrimp, and season with salt and black pepper. Cook for about 3-4 minutes until the seafood is just cooked through.

Make the Saffron Tomato Sauce

In the same skillet, add the saffron threads and crushed tomatoes. Pour in the white wine and bring to a simmer. Let it cook for about 5-7 minutes until the sauce thickens slightly.

Combine and Serve

Add the cooked fettuccine to the skillet, tossing to combine with the seafood and sauce. If the sauce is too thick, add reserved pasta water a little at a time until desired consistency is reached. Stir in the chopped parsley before serving.