WASHINGTON (Reuters) - The U.S. National Transportation Safety Board (NTSB) said on Wednesday it was opening an investigation into a March 3 fatal crash between a Ford Mustang Mach-E and two stationary cars on the I-95 interstate highway in Philadelphia.

In March, the NTSB said it was investigating the use of an advanced driver assistance system in a Ford Mustang Mach-E that was involved in a Feb. 24 fatal crash in San Antonio, Texas in which the Mach-E struck rear of a Honda CR-V that was stationary in a traffic lane on Interstate Highway 10.

Ford offers BlueCruise, an advanced hands-free driving system that operates on 97% of U.S. and Canadian highways with no intersections or traffic signals.

The NTSB said it is investigating in coordination with the Pennsylvania State Police, which did not immediately respond to a request for comment.

Ford said Wednesday it was recently made aware of this incident by the NTSB and has informed the National Highway Transportation Safety Association (NHTSA) as required.

NHTSA requires automakers to report all fatal crashes involving advanced driver assistance systems.

"We are researching the events of March 3 and collaborating fully with both agencies to understand the facts," Ford said.

NHTSA did not immediately comment.

The Philadelphia Inquirer reported the crash closed the busy section of I-95 for several hours after the fatal accident.

The NTSB has opened several investigations in recent years into advanced driver assistance systems including Tesla's Autopilot.