The National Transportation Safety Board, or NTSB, was an organization of the United States government which was charged with investigating accidents and disasters involving civil transportation, including criminal and terrorist attacks. NTSB agents were known for their patience, meticulousness, and objectivity.
After the destruction of Alaska Airlines Flight 442, an NTSB agent named Diana Christie, operating out of the Los Angeles Field Office, investigated the crash with the help of the then-fledgling Counter Terrorist Unit. (Trinity)
NTSB agents investigated the crash of the helicopter carrying Ambassador Shareef and his head of security, Farhad Salim, after it departed the Northwest Regional Operations Complex in Oregon. President David Palmer and his inner circle had persuasive reasons to suspect this was not an accident, but murder orchestrated by Roger Stanton and the Coral Snake conspirators. ("Day 2: 1:00pm-2:00pm")
The NTSB investigated a train derailment that occurred at 7:02am of Day 4 in the Santa Clarita Valley. There, they discovered that a man named Brody died from gunshot wounds, not due to injuries from the crash. It was later discovered that the shooter had taken a briefcase chained to the man's wrist containing the Dobson Override device. ("Day 4: 7:00am-8:00am")