sentences:  In a bombardment on 22 September 1917, the lock gates were hit causing the basin to drain at low water.Two years passed before the next attempt on the Ostend locks.The First Ostend Raid was conducted in tandem with the similar Zeebrugge Raid led by Acting Vice-Admiral Roger Keyes on 23 April 1918; a large scale operation to block the wider canal at Zeebrugge.