NEW YORK - Federal authorities have issued an emergency order instructing the Metro-North to modify its signal system following Sunday's deadly train derailment in the Bronx.

Authorities also said the railroad must put extra operators on lines where there are major speed changes. The MTA, which oversees the Metro-North, has agreed to comply with the order and submit an action plan by Dec. 31.

The Metro-North is meanwhile already getting hit with multimillion-dollar civil claims. According to legal experts, prosecutors will face tough choices on whether to press criminal charges against engineer William Rockefeller, who allegedly fell into a daze in the moments before the crash.

Rockefeller has been suspended without pay, but experts caution that his nodding off at the controls isn't necessarily a crime.

An attorney representing some passengers says his clients want to hold the Metro-North accountable for not installing safety equipment that may have prevented the accident.

The National Transportation Safety Board says that the train was going 82 mph as it approached a sharp curve near the Spuyten Duyvil station where the speed limit is 30 mph. It's investigation into the derailment is ongoing.