The first components of the Mulberry harbours were brought across on D+1 and the structures were in use for unloading by mid-June. One was constructed at Arromanches by the British, the other at Omaha by the Americans. Severe storms on 19 June interrupted the landing of supplies and destroyed the Omaha harbour. The repaired Arromanches harbour was able to receive around 6,000 tons of materiel daily and was in continuous use for the next ten months, but most shipments were brought in over the beaches until the port of Cherbourg was cleared of mines and obstructions on 16 July.