(Tacoma, WA)  --  Amtrak's president says the company will follow through on any recommended changes following the investigation into Monday's deadly derailment in Washington State.  President Richard Anderson said the company needs to continue to improve its culture of safety.  He said it's not acceptable that the company is involved in accidents like this one.  Anderson wouldn't speculate whether implementing speed controls called Positive Train Control would have prevented the accident.  He wanted to leave that determination up to investigators.