The cargo ship El Faro was supposed to have its boilers serviced a week after it headed out on what turned out to be its final voyage — in which it suffered a “hull breach” and power loss during a hurricane and sank to the bottom of the sea, investigators revealed on Tuesday.

A timeline released by the National Transportation Safety Board said that on Sept. 11, the ship’s owner got permission from the Coast Guard to shut down one of the boilers so it could be inspected during a trip. The inspectors then recommended that both be serviced during a drydock scheduled for Nov. 6.

But first, the container-laden ship had to make one more run.

Click here for the full report by NBC News.