A US Department of Defense report says that flawed workmanship and engineering by Lockheed Martin and Boeing, and fragmented lines of authority within the US Government, contributed to the failure of three Titan IVs and two Delta IIIs in 1998/9. The report identifies an "urgent need to clearly identify authority and responsibility". Another factor was a "premature shift of attention" towards the new-generation Evolved Expendable Launch Vehicles being built by Lockheed Martin and Boeing.
Source: Flight International