The Airbus A320, suffered the detachment of door L1 when boarding passengers by raising the gangway. On October 28, 2023, the Airbus A320, registered LZ-MDI was docked at parking spot B03 after arrival. The aircraft stayed overnight with the same jet bridge attached automatically throughout the night (07 hours). On October 29, 2023, at 06:39, during the boarding of passengers for the departure to Venice, Italy, without the presence of the jet bridge operator, both the audio and visual alarms of the jet bridge were triggered. The passenger disembarkation was temporarily halted on the order of the aircraft?s captain. The head of the jet bridge operators was immediately contacted by the handling supervisor. Shortly after, the metal structure of the jet bridge came into contact with the aircraft’s front door, causing it to be completely torn upwards. Probable causes of the serious incident (translated from French language final report): The analysis of the factual data from this event reveals that JH-Technique, the company responsible for the maintenance of the jet bridges at Mohamed V Airport, did not request certified spare parts from the manufacturer as recommended. Indeed, the maintenance needs of the jet bridges to maintain their functionality effectively require adherence to the manufacturer’s instructions. Additionally, the initial and periodic training on the maintenance tasks of the jet bridges provided by JH-Technique is neither validated by the manufacturer, nor by a civil aviation authority, nor by an accredited training organization. Furthermore, the examination of the maintenance data for the jet bridge revealed that the maintenance program is inappropriate. In summary, the serious incident could only be due to a failure of the maintenance system of said company, consequently leading to an imminent malfunction of the jet bridge mechanism, exacerbated by the non-compliance with operational procedures, including, among others, the absence of the operator during boarding operations. Contributory factors: – Exceeding the docking duration of the jet bridge to seven (07) hours instead of the four (04) hours recommended by the manufacturer for a “Night-Stop” aircraft; – Absence of the PBB operator at the jet bridge during the occurrence of the event, who should have intervened when the alerts were triggered; – Increased vibrations in the cable tray with each movement of the jet bridge.