Another tragic crane collapse has left 4 people dead and many more injured. This time the crane collapsed in Houston Texas at an oil refinery. The accident is under investigation and sources say that they don't know what would have caused the crane to collapse to the ground.

There has been a recent rash of crane collapses, the most recent in May that killed two in New York City. There are several federal and state agencies that are investigating the oversight of the crane industry to determine what other safety factors would be required to prevent future collapses.

Today's collapse is a reminder of the danger that can be faced in the crane industry. State and Federal agencies are beginning their preliminary work to access what caused today's collapse.