Update: Just checked their site and found no info on MH370 other than their investigators are helping and on March 12:
NTSB UPDATES STATEMENT ON MISSING B-777 INVESTIGATION
National Transportation Safety Board investigators who traveled to Kuala Lumpur over the weekend are assisting Malaysian authorities who are leading the search efforts for the Boeing 777 that went missing five days ago.
Investigators with expertise in air traffic control and radar are providing technical assistance to the Malaysian authorities who are working on locating the missing jetliner.
The NTSB plans no further releases of information on the investigation.