The accident was later found to have occurred due to excessive speed on the Gulf Curve, the sharpest on the Central's lines.

[2][3] The train departed New York City's Grand Central Terminal at 6:50 p.m. with approximately 250 passengers on board with a scheduled arrival in Chicago at 1:10 p.m. on April 20.

[7] The accident happened 2,895 feet (882 m) east of the Little Falls train station where the tracks run parallel to the north shore of the Mohawk River, on the Gulf Curve, the sharpest curve in the New York Central system, a 7-degree bend, where the speed limit was 45 miles per hour (72 km/h).

[2][9] The train was pulled by a 316,000-pound (143,000 kg)[11] steam engine number 5315, a NYC Hudson 4-6-4 type in service since 1931.

The fourth car came to rest on its side on East Main Street which ran parallel to the tracks.

[3] There was initial speculation that the roadbed may have been weakened by heavy spring rains[13] but this was not cited in the final report.

[6] Rescue operations were made more difficult by rain, sleet and snow that began in the early morning hours of April 20.

Injured victims were sent to hospitals in Little Falls, Frankfort, Herkimer, Utica, and Ilion as well as to hotels, private homes and churches.

[6] Thirty-five Chinese nationals en route to San Francisco in the custody of a United States Marshal, who were being deported for entering the US illegally, were in the last car and were uninjured.

)[11] Dozens of other trains were delayed in the days following the wreck; the site was bypassed by routing trains, including the 20th Century Limited, the Commodore Vanderbilt, and the Water Level Limited between Utica and Schenectady over West Shore Railroad tracks.

[13] A realignment to reduce the angle of the curve was completed on November 19, 1947, which required diverting the river farther south and filling in the old channel.

[16] He may also have been worried about being put further behind schedule once reaching Utica because one of the Pullman cars, with passengers destined for the northern New York towns of Saranac Lake and Lake Placid, would have to be switched out of the train there to join a different northbound Adirondack Division train.

[11] A memorial marker was erected by the Gulf Curve Chapter of the National Railway Historical Society in 1990 at the junction of River Road and Route 5 mounted to a boulder (43° 2.563' N, 74° 50.943' W).