In a large pot of boiling salted water, cook the spaghetti until al dente.
Meanwhile, in a large, deep skillet, heat the olive oil. Add the garlic and cook over moderate heat until golden, about 1 minute. Add the curry powder, crushed red pepper and a pinch of salt and cook, stirring, for 1 minute. Add the wine and cook over high heat until evaporated, about 2 minutes. Add the tomato sauce and cook over high heat, stirring occasionally, for 4 minutes. Add the shrimp, squid and scallops to the skillet and simmer, stirring, until just cooked through, about 3 minutes.
Drain the spaghetti, add it to the skillet and toss well. Season with salt and sprinkle on the parsley. Transfer the spaghetti to bowls and serve.