Philadelphia — The National Transportation Safety Board held a press conference Thursday afternoon to explain its investigation procedures for Wednesday’s potentially fatal boat accident.

But board member Robert Sumwalt, the only one to speak at the press conference, spent more time telling local media that NTSB still has few answers and it will be a long time before some of their most pressing questions are answered.

Thirty-seven people were thrown into the Delaware River Wednesday afternoon when a barge collided with the amphibious duck boat they were on. Thirty-five people were immediately rescued.

The U.S. Coast Guard suspended the search for the two missing people on Thursday night.

When a television reporter asked Sumwalt what he thought about tourists getting mixed up in an accident involving the industry side of the marine sector, Sumwalt’s only response was “It’s tragic.”

At the time of the collision, the duck boat was at a halt on the river, waiting for assistance after a reported engine fire disabled the engine. A tugboat was pulling the barge.

NTSB is taking the lead on the investigation and questions are being deferred to board member Robert Sumwalt and lead investigator Tom Roth-rothy, who are in Philadelphia supervising the investigation team.

Sumwalt said that NTSB expects to have investigators on the scene for seven to 10 days total, meaning they could depart as early as the end of next week.

Investigators will take all of the data and information collected and bring it back to Washington, D.C., where NTSB is headquartered. It will likely take several months to put all the pieces together and determine everything that went wrong Wednesday afternoon.

While on the scene, investigators will be gathering all kinds of information and data on the actual boats involved, their operating procedures, their crew members and their emergency preparedness and response. That will come form actual inspections of the boats, records and equipment and extensive interviews with passengers, crew and first responders and rescuers.

For local coverage of the accident, you can check out the Philadelphia Daily News and Philadelphia Inquirer at www.philly.com. Thursday’s main story on the accident focuses on confusion about why the tug boat was unaware of the duck boat’s presence.

Keep checking back for more updates and some photos of the accident site. Contact reporter Ariel Zirulnick at ariel.zirulnick@news21.com if you have any leads.