It occurred in Manikganj District, Bangladesh. Even though it lasted only a few minutes, it was the deadliest tornado on record.
It happened on April 26th, 1989 at 6pm local time. It was estimated to be one mile wide.
1300 estimated deaths injured homeless. Houses were completely destroyed. Prior to the tornado, there was a drought for 6 months. One factor that is believed to intensify the conditions.
I didn't manage to find who helped out, but I'm guessing the police managed to save some after since the tornado was unexpected. There was no specific cost to rebuild, but I am guessing somewhere in the millions! The Fugita scale is unknown due to poor housing and lack of data.