WASHINGTON, April 11 (Reuters) - The National Highway

Traffic Safety Administration (NHTSA) said Thursday it is

investigating a March 3 fatal crash between a Ford Mustang

Mach-E and two stationary cars in Philadelphia in which an

advanced driver assistance system could have been in use.

This is the second recent Ford crash under investigation by

the auto safety regulator and the National Transportation Safety

Board (NTSB) in which a driver assistance system is suspected of

being in use.

The March 3 crash involved the Ford striking two

stationary vehicles on the I-95 interstate highway in

Philadelphia killed two people and shut down traffic for hours.

The NTSB said it is investigating in coordination with the

Pennsylvania State Police, which declined to comment.

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.

In March, NHTSA and the NTSB said they were 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.

A San Antonio police report said the Ford had "partial

automation" engaged at the time of the crash.

Ford said it was recently made aware of this incident by the

NTSB and informed NHTSA, which 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 has opened special crash investigations into the

two recent Ford crashes. The agency typically opens more than

100 special crash investigations annually into emerging

technologies and other potential auto safety issues.

Since 2016, NHTSA has opened more 40 Tesla special crash

investigations in cases where driver systems such as Autopilot

were suspected of being used, with 23 crash deaths reported to

date. Tesla in

December agreed to recall 2 million

vehicles to install new safeguards for Autopilot.

The NTSB has opened several investigations in recent

years into advanced driver assistance systems including Tesla's

Autopilot.