Disclosed is a system and method for particle monitoring for a head disk assembly (HDA) to detect a head disk interface (HDI) event. A particle monitoring system includes a particle detector, an air sampling device, and a computer. The air sampling device is coupled to and in fluid communication with the particle detector. The air sampling device extends into the HDA to obtain an air sample. The particle detector is used to detect particles contained in the air sample. The computer is coupled to the particle detector and is configured to: monitor the particles detected by the particle detector; and declare an HDI event if the particles detected in the air sample match a pre-defined characteristic.