If your gang turf is under attack, go to a save point and save the game. When it is done saving, your turf will no longer be under attack and it will still be yours. Additionally, when your hood is under attack, find a police car or motorcycle, fire truck, ambulance, or taxi. Get in and click Right Analog-stick to start the vehicle's missions. Then, click Right Analog-stick again to exit and your hood will be safe.