The possibility of supershear rupture on the Palu-Koro Fault was raised in 2017. Indonesian authorities confirmed that no one had been able to contact a single person from Donggala, the closest town to the epicentre. As of 1 October, contacts were still hampered by downed telecommunication lines. Aftershocks The mainshock was followed by a series of aftershocks, with 14 of M≥5.0 in the first 24 hours. Since then, a total of 150 aftershocks have struck the region. Intensity The earthquake was felt over a wide area. The strongest shaking (MMI X) was felt in some parts of Palu City. In other areas of the city, the Mercalli intensity was evaluated to be VII, based on damage in single and double-story buildings. Four-story structures like a hotel and shopping mall moderate to heavy damage and the intensity was assigned VIII. Major damage to the Palu IV Bridge was eventually given MMI IX. Tsunami A tsunami warning was issued in Palu and Donggala at 18:07 WITA. Warnings were sent via SMS by the Indonesian Ministry of Communication and Information. Residents of Donggala were told to expect tsunamis with heights of 0.5 to 3 metres, while residents in Palu were told to expect tsunamis with heights of less than 0.5 metres. The tsunami, however, struck higher than expected. Residents of Palu reported waves with heights of more than 2 metres while several others stated that the waves managed to reach the second floor. Indonesian officials calculated the estimated time of arrival of the tsunami. Calculations suggested that the tsunami would arrive in Palu approximately 20 minutes after the earthquake. Around 18:27 WITA, the Indonesian meteorological agency (BMKG) in Mamuju detected tsunamis. A tsunami warning was issued, and later lifted. The BMKG claimed the warning was lifted after the tsunami had struck, the timing is clear, but since there was a one-hour time difference between the sunset in Palu and Java where many Indonesian in social media reside, many thought the warning was lifted before the tsunami hit, because the video that circulating around was after the sunset, while the warning lifted around 18:27 WITA it was 17:27 WIB for most of these people reside where the sun is still high up, resulting in the agency being criticized on social media. Even though officials did send warnings via telephone and television, tsunami alarms were not activated. The Palu Nomoni Festival in Talise Beach continued