A man died of his injuries at the hospital Friday after falling 20 feet off a ledge onto the eastbound lanes of Interstate Highway 90 in Boston.

I-90 is also called the Massachusetts Turnpike.

The 50-year-old man, unnamed by authorities, was found on the underground ramp to the Copley Square exit in Boston at 8:20 a.m., Massachusetts State Police said in a release.

Initially, police thought the man had been struck by a driver who left the scene. However, troopers then found the ledge 20 feet up.

On the ledge were a sleeping bag and toiletries, suggesting the man lived there.

A trauma surgeon who operated on the victim said his fatal injuries were not consistent with a vehicle strike and instead matched those incurred by a fall, MSP said.

The discovery and investigation shut down the nearby exit ramps for two hours, with all ramps reopening by 10:20 a.m., the Massachusetts Department of Transportation told Boston NBC affiliate WBTS.

• Brad Matthews can be reached at bmatthews@washingtontimes.com.