Navy divers have begun a massive, five-day operation to defuse the largest unexploded World War Two bomb ever found in Poland.
It's called a "Tallboy" -- used by the British air force back then -- and underwater footage gives an idea of its size - and the scale of the task.
The bomb was found in the Piast Canal, which connect the Baltic Sea with the Oder River.
Michal Jodlowski commands a navy minesweeper on the job.
"What we have to do with here is the second biggest conventional bomb of World War Two. The bomb weighs 5,400 kgs. Out of this 2,400 kgs is the explosive material. It is very powerful, an equivalent of 3,600 kgs of TNT (Trinitrotoluene), the probability of shrapnel spreading above water is very high."
Dubbed the "earthquake" bomb, the Tallboy was dropped by British planes in 1945 during an attack on a German cruiser.
This illustration shows just how big it is - and how devastating it might have been.
Complicating matters: The site is near a town with a liquefied natural gas terminal.
According to local media, more than 700 people have had to be evacuated from their homes during the operation.