"The derailment of Northeast Regional Train 188 was a terrible tragedy that we are responding to with every resource we have available," Joe Boardman, Amtrak president and chief executive officer, said in a statement Thursday evening.
"Amtrak takes full responsibility and deeply apologizes for our role in this tragic event."
The train derailed Tuesday night in Philadelphia when taking a curve at 106 mph, more than twice the speed limit,
Boardman did not specify how many people are being helped with medical bills and funeral expenses or what percentage of their bills is being paid by the company.
Amtrak did not immediately respond to a request for additional information.
"With truly heavy hearts, we mourn those who died," Boardman said in the statement. "Their loss leaves holes in the lives of their families and communities."
He thanked first responders and medical personnel for saving lives, and said the company is focused on learning what went wrong Tuesday night.
"Our goal is to fully understand what happened and how we can prevent a similar tragedy from occurring in the future," Boardman said. "We will also continue to focus on completing positive train control implementation in the Northeast Corridor by December of 2015."
The technology uses global positioning satellites, sensors and sophisticated computers to track trains and prevent their crews from ignoring signals and speed limits.
Congress has mandated that it be installed nationwide by the end of the year, but some railroad companies will miss the deadline and are lobbying for a delay.
On Thursday, NTSB member Robert Sumwalt told reporters, "I can confidently say that an operational positive train control [system] would have prevented this accident."