Tugboat warned before collision

Newly released radio transmissions during a collision on the Mississippi River indicate a tugboat involved in a wreck with a tanker was repeatedly warned that the massive vessel was headed toward it but did not respond.

The Coast Guard released results of its preliminary investigation and the audio recordings.

In the radio chatter just before the July 24 collision, the pilot of the tanker audibly becomes increasingly distressed as the ship heads toward the tugboat, which was pushing a barge.

The collision caused thousands of gallons of oil to spill.