HIGHLAND, Ill. – Authorities have identified three people who died Wednesday morning after a Greyhound bus slammed into three big rigs parked near an Illinois rest stop.

The Madison County Coroner’s Office has identified the victims as Juan E. Vasquez-Rodriguez, 34, of Passaic, New Jersey; Buford Pena, 71, of Supai, Arizona; and Bradley L. Donovan, 47, of Springfield, Illinois.

The coroner’s office said the three suffered various injuries in connection with their deaths, including head, abdominal and thoracic trauma.

At least 14 others were hurt in the crash, which happened when the bus struck three big rigs parked on the shoulder of Interstate 70. The passenger bus was supposed to pull in at the Greyhound station in downtown St. Louis from Indianapolis, and was just miles away from reaching its destination.

Investigators are still trying to determine circumstances leading up to the crash. NTSB board member Tom Chapman said investigators will spend the next 6-10 days evaluating the scene of the crash, and it could take up to 24 months to release a final report on what happened.

“Our investigators will work to thoroughly document relevant evidence and gather additional factual information,” said Chapman. “Our mission to understand not just what happened, but why it happened and to recommend changes to prevent it from happening again. These are the first steps in a lengthy investigative process.”

With the crash involving three big rigs, many are concerned as to what this means for truck safety. Truckers who spoke to FOX 2 on Wednesday have expressed the need for more parking spaces and rest spots along major highways like Interstate 70.

Chapman says the NTSB will review recommendations related to truck safety and resting spots.

“If we find in the course of our investigation that it’s appropriate to make recommendations before the investigation is completed, we have that ability and authority to do that,” said Chapman. “We will make emergency recommendations when it is appropriate to do so, when we find during the fact-finding effort that some condition occurs that needs to be addressed more quickly than it would be if the final results of our investigation held it up.”

Chapman says the bus that crash was a 2014 model equipped with seatbelts, though that wasn’t required of such buses until 2016.

The NTSB says it will investigate factors like human performance, highway factors and technical reconstruction that might have led up to the crash. Chapman encourages any witnesses with relevant information to contact them via email at witness@ntsb.gov or by phone at 866-328-6347.

Officials from the Illinois State Police are assisting the NTSB with the investigation. As for the victims who died, the Madison County Coroner’s Office says another routine toxicology test is pending to determine the final cause of death.