You will often see the terms "accidental death" and " wrongful death " used synonymously in Pennsylvania. However, they are examples of two different terminologies used by the legal system -- one criminal and one civil -- that refer to the same event.
Accidental death is a term used in criminal law.  It refers to the unintentional death of a person caused by another who was engaged in a reckless activity sufficient to warrant criminal prosecution.
Insurance companies, most commonly in life insurance and automobile insurance policies, often also use the term accidental death.   The use of such term by an insurance company should not be confused with the term as used within the legal system.  In most instances, the term accidental death in an insurance policy refers to the death of an individual due to an accident, regardless of who may be responsible for the accident and how it happened.
A wrongful death claim, on the other hand, is brought in civil court.  Wrongful death civil suits state that the defendant in the case was responsible for the deceased's death, even if they did not intend for the person to be injured or die. Civil cases only require a preponderance of evidence supporting the claim that the defendant could have avoided causing the death if they had only exercised reasonable care (not been negligent or reckless in their actions). The outcomes of wrongful death civil suits are monetary awards paid to the surviving spouse, children, or parent of the person who died as a result of the defendant's actions. The defendant, however, faces no criminal punishment if found liable only in civil court.

Some people choose to bring civil wrongful death suits against a defendant whom the District Attorney either decided not to criminally prosecute for the death of an individual, or the defendant was tried but not convicted of a crime.  Because criminal and civil law are not the same, it is possible that a person goes to trial twice for the same action without invocation of double jeopardy protection.  The most famous examples of this are the O.J. Simpson trials for the deaths of Ron Goldman and Nicole Brown. Simpson was tried and found not guilty for those deaths in criminal court, but the families of Goldman and Brown later successfully filed a wrongful death civil lawsuit.

In conclusion, while it is not technically wrong to use "wrongful death" and "accidental death" interchangeably, as they do refer to the same result for the victim under Pennsylvania law, the terms are properly used either to describe a criminal issue (accidental death) or a civil issue (wrongful death).