The steamboat struck a submerged object .
The steamboat sank in the Mississippi River 4 nautical miles ( 7.4 km ) upstream of the confluence of the Ohio River with the loss of 20 - 40 lives .
The steamboat struck a submerged object and sank in the Mississippi River 4 nautical miles ( 7.4 km ) upstream of the confluence of the Ohio River with the loss of 20 - 40 lives .