NTSB: Plane recorders recovered from Lewis Katz's doomed jet

Investigators took a big step Monday evening toward uncovering the mystery behind the doomed fate of the Gulfstream IV jet that crashed Saturday night off the runway of a Massachusetts airport and killed seven people, including Philadelphia philanthropist and businessman Lewis Katz.

Two crucial flight recording devices were recovered at about 5 p.m. from the charred wreckage of the jet in Bedford, Mass., according to a tweet by the National Transportation Safety Board.

"Cockpit voice recorder and flight data recorder just recovered from Gulfstream IV involved in Saturday's accident in Bedford, MA.," the NTSB tweeted at 5:21 p.m.

No further information was immediately available. The discoveries came shortly after a 5 p.m. press conference, at which federal investigators said the cause of the crash remained unknown.

The NTSB also announced it would hold a final media briefing at 5 p.m. Tuesday.

Along with Katz, three New Jersey women, two pilots and a flight attendant died in the catastrophe.