A computer implemented method for detecting a fall of a user within an internal space of a building, the method comprising receiving a first air-pressure sensor signal indicative of change in air-pressure measured at a device worn by the user； receiving a measurement indicative of change in air-pressure within the internal space of the building；and determining the fall of the user based on the change in air-pressure measured at the device and the measurement indicative of change in air-pressure within the internal space of the building.
