IS MY LANDLORD LIABLE FOR DAMAGES CAUSED TO MY APARTMENT AND ALL MY BELONGINGS FOR NEGLIGENCE?

No, they are not liable for the costs of your personal property. Faulty or inoperative fire alarms didn't cause the damage to your property, nor would they have prevented the damage had they been functioning properly. Had you been injured because of that issue, there would be liability. Fire alarms are there to prevent personal injury.You apparently escaped without personal harm. The loss of your personal possessions should be covered by your renter's insurance policy. Let me guess. You didn't have renter's insurance.