Just about a year ago, the Orbital ATK Antares rocket on its way to resupply the International Space Station blew up shortly after launch. While Orbital ATK is responsible for their own accident investigation, NASA established an independent review team, and they released their findings earlier this week.
In a nutshell, the LOX turbopump Hydraulic Balance Assembly and thrust bearing designs were not sufficiently robust for the Antares mission, and they found foreign object debris (FOD) and workmanship defects in the LOX turbopump. One or more of those could have brought the vehicle down. Several recommendations were made to Orbital ATK for more sensors, more acceptance and qualification testing, more thorough inspections, and better contamination control.