Just in time for East End revelers to return for the work week, the Long Island Rail Road’s Montauk branch resumed service on Memorial Day after an early Saturday morning derailment forced thousands of getaway travelers to search for other options during one the busiest weekends of the year.

The 7:04 a.m. train bound for Jamaica was the first westbound train to leave Montauk this morning, according to an LIRR tweet.

But LIRR riders should still expect residual delays.

On Friday, there were more than 8,600 LIRR train riders headed to the Hamptons, according to a spokesman. Last year on the Saturday of Memorial Day weekend, the railroad carried 4,000 people east of the Speonk station. In recent years, Montauk, which sits at the easternmost tip of Long Island, has become the official partying spot in the Hamptons, overwhelming the residents of the once laid-back hamlet as well as its septic system.

The train problems began at 1 a.m. on Saturday, when an eastbound Montauk passenger train sideswiped an empty work train near Speonk, causing both cars on both trains to derail.

Although no one was hurt, the track damage was extensive, according to the LIRR.

Crews began working around the clock and by Saturday afternoon, some service was restored to the South Fork with the help of bus service between Patchogue and Hampton Bays and an LIRR shuttle train between Hampton Bays and Montauk. On Sunday, travelers could find limited service to and from Speonk.

Over the weekend, LIRR urged travelers to use other options to make their way to the East End, such as the Hampton Jitney service, which reported a spike in service.

The derailment is being investigated by the LIRR, which adds that it is also "in consultation with the Federal Railroad Administration and New York State Passenger Transportation Safety Board."