This is, how it was done:
Out of the 133 engaged RAF soldiers, 54 died during the attack.
Casualties among the civilians were 1,284 persons (amongst them 700 Russian female forced labourers).
There were now 'vital' bridges destroyed, since there is and was nothing of any importance to connect (leaving out the fact that of course some villager where hindered for 4 weeks to go from one village to the next on the shortest way).
The other damn were the Eder
43 dead civilians, rebuilt within 4 months,
and the Sorpe, where only small damages happened.
RAF : Bomber Command Daily Report 18th May 1943 Extract