The NTSB has boarded the cargo ship that crashed into the Baltimore Key Bridge early Tuesday morning and was able to recover the so-called "black box" that could shed light on what went wrong with the massive freighter.

NTSB Chairwoman Jennifer Homendy says investigators are looking at the data and hope to share more information later on Wednesday about what the data said and a timeline of events before the fatal accident.

"It's a critical piece of our investigation," Homendy said Tuesday of the ship's voyage data recorder.

In an interview on CNN Wednesday morning Homendy said they are concentrating on gathering evidence from the scene that is perishable.

"Right now it's getting what will disappear once this is cleaned up. That is our focus," Homendy said.

She says the analysis will come later but evidence collection is the current priority.

They are also planning to interview the crew and pilots who were on the vessel on Wednesday.

They also plan to interview fire and rescue personnel who responded to the scene as well as people who were on the bridge.

She said the NTSB will look into the possibility that the ship had dirty fuel that caused the power problems. Homendy cautioned that it was just one of many things that they would investigate and it was far too early to speculate that being the cause of the ship's problems.

Homendy said the safety record of the ship and its owners will be investigated.

The United States Coast Guard ended its search late Tuesday for six construction workers who were on the Francis Scott Key Bridge when it was rammed by the cargo ship Dali and collapsed into the Patapsco River.