Fresh fettuccine with shrimp and leek sauce

Ingredients

• 1/2 teaspoon kosher salt, plus more for the pot
• 6 tablespoons extra-virgin olive oil
• 6 garlic cloves, peeled and sliced
• 2 leeks, halved lengthwise, white and -light--green parts thinly sliced
• 12 ounces zucchini, sliced into -1/4--inch--thick -half--moons
• 1 pound fresh fettuccine
• 1/4 teaspoon crushed red pepper flakes
• 2 cups San Marzano canned whole tomatoes, crushed by hand
• 1 pound medium sized shrimp shelled and divined
• 1/4 loosely packed cup fresh basil leaves, chopped