The National Transportation Safety Board (NTSB) confirmed Wednesday morning that search and recovery efforts are still underway after an Amtrak train derailed late Tuesday evening in the Port Richmond neighborhood.

NTSB board member Robert Sumwalt said that they hope to provide more information on the cause of the derailment within the next 24 to 48 hours.

“The search and recovery effort will take precedence over our active investigation,” Sumwalt said. “We have not started to very carefully document the wreckage at this point.”

So far, six have been confirmed dead and over fifty injured. Several presumed passengers have been reported missing.

“We’re not going into who is missing,” Mayor Michael Nutter said at a press conference in the Port Richmond Wednesday morning. “We have to be sensitive to who may have had family on the train…Again, this is a horrific scene and we need your patience and understanding.”

As of 11 a.m. Wednesday morning, Sumwalt confirmed that they do not have any information from the train’s recorders.

“We basically…and I want people to understand…We just got here,” said Sumwalt, who had been on the site since 5 a.m. “We have a lot of questions, and we intend to answer many of those questions in the next 24 to 48 hours.”

U.S. Senator Bob Casey (D-PA) released a statement emphasizing the Northeast Corridor as a crucial travel route for millions of Americans. 

“It’s critical that we do all we can to assess the results of the investigation into this crash and take appropriate steps to prevent derailments in the future,” he said.

Casey recently urged Amtrak to hasten its upgrades to 30th Street Station in time for Pope Francis’ visit for the World Meeting of Families in Philadelphia. 

But for the several years, Amtrak CEO Joseph Boardman has faced a funding challenge. In a 2013 interview with AL DÍA, he stressed that the Northeast Corridor rail lines have had “serious” problems since 1976.

The transit company faced $6 million in pending repairs and the private sector wouldn’t chip in at the time, Boardman added.

“I’ve focused on repairing rails rather than laying new ones,” he said two years ago. “In my testimony before Congress, I asked for $373 million a year for the next 15 years solely for the purpose of repairing the rail lines.”