Elon Musk: launch pad accident ‘most difficult failure' in SpaceX’s history

After a week of public silence, Musk says the company is investigating the accident, its second in 15 months

SpaceX chief executive Elon Musk is calling last week's launch pad accident the "most difficult and complex failure" in the company's 14-year history.

After a week of public silence, Musk said via Twitter the company is still investigating the accident, its second in just 15 months.