This document describes a GSM-based gas leakage detection system that was designed and tested. The system uses an MQ-2 gas sensor to detect combustible gases like LPG, an Arduino Uno microcontroller, a GSM module to send alert messages to users' phones, and a buzzer and LEDs for audible and visual alarms. When gas is detected above a threshold, the system sends an alert message, sounds the buzzer, and turns on a red LED. If the user replies "ALERT," neighbors will also be notified. The system was tested successfully using butane gas and could detect leaks and send alerts as intended to improve safety during gas emergencies when people may not be home