Generally speaking, the United States has taken a leading role in aviation safety. However, it failed to act first after news broke that two planes made by Boeing had been involved in serious accidents. It is believed that software used on the 737 Max jets led to the crashes, and they could have posed a danger to Florida residents or others who may have flown on them in the future.
The Federal Aviation Administration (FAA) has grounded planes in the past after safety issues became apparent. In 2013, Boeing 787 Dreamliners were not allowed to fly because of battery fires. In 1979, McDonnell Douglas DC-10 planes were not permitted to fly after crashes that resulted in numerous deaths. The acting administrator for the FAA tried to defend the delay in grounding the 737 Max jets by saying that he led a fact-based organization.
The actual announcement to ground the planes was made by President Trump as opposed to the leader of the FAA. Airlines were allowing passengers to change their tickets for free if they didn't want to fly on the 737 Max. However, airlines were also saying that the craft was safe to travel on before the announcement was made to keep them on the ground. While some wondered why it took so long to ground the plane, others said doing so was merely a public relations decision.
Multiple parties may be liable when airplane crashes occur. For instance, the company that made the plane or the pilot who made an error during a flight could be deemed negligent for a crash. Those who are injured in crashes may be entitled to compensation for their injuries, and the same may be true for the families of those who are killed.