Long Island Rail Road crews are working to repair damage following a train derailment in Speonk that has snarled rail service to the South Fork on the busy Memorial Day weekend.

The railroad says it expects normal service to resume for Memorial Day on Monday. A holiday schedule will be in place as planned.

As News 12 has reported, a train sideswiped a passenger train Saturday morning, causing the derailment and extensive track damage. About 30 people were aboard the passenger train, but no injuries were reported.

The LIRR halted service on its Montauk branch east of Patchogue. Instead, the railroad is running bus service from Patchogue to Hampton Bays, and a shuttle train to and from Montauk for Sunday. It was advising riders to consider alternate branches, or alternate methods of transportation, until full service resumes -- which is expected on Monday.

In a statement, the LIRR said that its employees have been "working around the clock since the incident to re-rail the derailed locomotives and passenger car, clear the trains from the area, rebuild a destroyed switch, repair extensive damage to two other switches, replace and repair related signal components, and rebuild hundreds of feet of main line track that were heavily damaged." 

"I thank all the hard-working men and women of the LIRR who responded to the call immediately and have been laboring extensively throughout this holiday weekend," said LIRR President Phil Eng. "Our employees' immediate response to this unexpected incident, and others like it, shows their dedication to our customers."

The cause of the incident is under investigation by the LIRR, in consultation with the Federal Railroad Administration and New York State Passenger Transportation Safety Board, according to the railroad.