RONKONKOMA - Hazmat crews were called to the Ronkonkoma train station overnight.
The emergency teams dressed in protecting suits were seen checking out a train.
Officials say an unknown liquid was reportedly found in a container on an eastbound train just after midnight.
As a precaution, the crews were called to investigate.
News 12 Long Island has learned the liquid was harmless but its content is still not known.
Train service was suspended for two hours. This morning, all trains are back on or close to schedule.