There were three signals spaced at three-quarters of a mile, a quarter of a mile, and 500 feet (150 m) from the draw bridge, and an automatic derailing device fifty feet beyond the third signal. The bridge span had to be down and locked electrically before the signals and derail devices could be cleared for movement on the track. Conversely, all the devices had to be in their most restrictive positions before the bridge could be unlocked and raised. The train ran through two signals and was derailed automatically; the automatic derailer was designed to knock the wheels off the track so that the resistance of the ties and ballast against the train's wheels would bring a slow-moving derailed train to a stop. Train #3314, although derailed, was moving at such a great speed that it did not have sufficient distance to stop before diving off the bridge.
The Interstate Commerce Commission, the New Jersey Public Utilities Commission, and the United States Army Corps of Engineers each conducted separate inquiries into the wreck, and all three found that the absence of a "dead man's control" was one primary cause of the accident. After the inquiries, the New Jersey Public Utilities Commission ordered the railroads to install such devices on all passenger locomotives operating in New Jersey. Some Jersey Central locomotives were equipped already with such devices, but this did not include the engine leading CNJ train #3314 on the day of the wreck. The railroad claimed that such a device was not always necessary, because all their trains had two crewmen in the locomotive cab. If the engineer was incapacitated somehow, the fireman would assume control of the locomotive.
An autopsy found that the engineer, 63-year-old Lloyd Wilburn, had indications of hypertensive heart disease, but that he had died of asphyxia due to drowning. However, no reason could be found to explain why fireman Peter Andrew, 42, could not or did not stop the train. Investigators raised the wreckage and did not find any defect of the braking system on the locomotives and coaches; it was also determined that the signal system and derailing device on the bridge had functioned properly. Lacking more definitive evidence, it was presumed that the engineer had somehow become incapacitated in the cab and the fireman failed to take appropriate action to stop the train. The presence of a "deadman control" in the locomotive cab might have averted the catastrophe, and, while the I.C.C. only "recommended" the installation of these devices, the New Jersey Board of Public Utilities directed that the railroad install them in all of its locomotives.
Forty-eight people died in the wreck, including former New York Yankeessecond basemanGeorge "Snuffy" Stirnweiss and James Carmalt Adams, the brother-in-law of author Kurt Vonnegut. The railroad had a number of legal actions brought against it, which were all settled out of court. The two locomotives, #1532 and #1526, were raised, rebuilt by the Electro-Motive Division of General Motors (EMD) and returned to service. Locomotive #1532 retained its original number, while the #1526 was renumbered #1531. They served primarily as freight locomotives, although the #1532 was photographed in passenger service after its return from EMD. The Newark Bay lift bridge was last used during 1978 and was determined to be a hazard to navigation; it was demolished during the 1980s.