Good News: a SpaceX Cargo Resupply is Off to the Space Station. Bad News: Failed Hydraulics in the Grid Fins Caused the First Stage Booster to Crash Into the Ocean

"Grid fin hydraulic pump stalled, so Falcon landed just out to sea. Appears to be undamaged & is transmitting data. Recovery ship dispatched." he said, adding later, "Pump is single string. Some landing systems are not redundant, as landing is considered ground safety critical, but not mission critical. Given this event, we will likely add a backup pump & lines."