Disclosed is a battery interconnected detection and alert device system with building structure vibrational alert. The system includes of one or more alert devices wired into a dedicated circuit with a single location housing a DC power backup source, such as a rechargeable DC battery. The DC power backup source may be replaceable or rechargeable with DC current from an AC-DC transformer-rectifier, a photovoltaic cell, or other means. An electrical relay within the system provides a current to the dedicated circuit by selecting between the line-voltage alternating current source and the DC power backup. When activated, the detection and alert device generates a distinctive pulsed vibrational alert transmitted through the building structure to beds and other furniture resting on the floor, and additionally transmitted through the air as pressure waves which are perceived by hearing-impaired and other persons alerting them to a possible emergency situation.