In 1755, the earthquake struck on the morning of 1 November, the holiday of All Saints' Day. Contemporary reports state that the earthquake lasted between three and a half and six minutes, causing fissures 5 metres (15 feet) wide to open in the city centre. Survivors rushed to the open space of the docks for safety and watched as the water receded, revealing a sea floor littered with lost cargo and shipwrecks. Approximately 40 minutes after the earthquake, a tsunami engulfed the harbour and downtown area, rushing up the Tagus river,[5] "so fast that several people riding on horseback ... were forced to gallop as fast as possible to the upper grounds for fear of being carried away." It was followed by two more waves. In the areas unaffected by the tsunami,[citation needed][clarification needed] fire quickly broke out, and flames raged for five days.