The spate of recent aviation disasters and close calls have people worried about the safety of flying.

The midair collision that killed 67 near Washington, the fiery plane crash in Philadelphia and now a missing plane in Alaska are only the most high-profile disasters. There was also a Japan Airlines plane that clipped a parked Delta plane while it was taxiing at the Seattle airport earlier this week and a United Airlines plane caught fire during takeoff at the Houston airport Sunday after an engine problem sparked a fire on the wing.

That’s not even to mention the security concerns that arose after stowaways were found dead inside the wheel wells of two planes and aboard two other flights. And don’t forget about the time that a passenger opened an emergency exit door on a plane while it was taxiing for takeoff in Boston.

So of course people are wondering whether their flight is safe?

What happened in the worst incidents?

The Jan. 29 collision between an American Airlines passenger jet and an Army helicopter killed everyone aboard both aircraft. It was the deadliest plane crash in the U.S. since Nov. 12, 2001, when a jet slammed into a New York City neighborhood just after takeoff, killing all 260 people on board and five on the ground. There hadn’t even been a deadly crash of any kind involving a U.S. airliner since February 2009.

Crashes are more common involving smaller planes like the single-engine Cessna that went missing in Alaska on Thursday with 10 people aboard. Crews were searching for that plane Friday.

A medical transportation plane crashed in Philadelphia on Jan. 31, killing the six people onboard and another person on the ground. That Learjet generated a massive fireball when it smashed into the ground in a neighborhood not long after taking off from a small airport nearby.

How worried should I be?

Fatal crashes attract extraordinary attention partly because they are rare. The track record of U.S. airlines is remarkably safe, as demonstrated by the long stretch between fatal crashes.

But deadly crashes have happened more recently elsewhere around the world, including one in South Korea that killed all 179 people aboard in December. There were also two fatal crashes involving Boeing’s troubled 737 Max jetliner in 2018 and 2019. And last January, a door plug blew off a 737 Max while it was in flight, raising more questions about the plane.

And federal officials have been raising concerns about an overtaxed and understaffed air traffic control system for years, especially after a series of close calls between planes at U.S. airports. Among the reasons they have cited for staffing shortages are uncompetitive pay, long shifts, intensive training and mandatory retirements.

President Donald Trump added to those concerns Thursday when he blamed the midair collision on the “obsolete” air traffic control system that airports rely on and promised to replace it.

But even with all that, Transportation Secretary Sean Duffy went on Fox News earlier this week and tried to assure viewers that air travel is “way safer than traveling in a car and train. This is the safest mode of transportation.”

And the statistics back that up.

The National Safety Council estimates that Americans have a 1-in-93 chance of dying in a motor vehicle crash, while deaths on airplanes are too rare to calculate the odds. Figures from the U.S. Department of Transportation tell a similar story.

What is being done?

The National Transportation Safety Board and Federal Aviation Administration are investigating these recent crashes and close calls to determine what caused them and look for ways to prevent similar incidents.

There have already been troubling revelations about the midair collision, but it will take more than a year to get the full report on what happened.

The NTSB always recommends steps that could be taken to prevent crashes from happening again, but the agency has a long list of hundreds of previous recommendations that have been ignored by other government agencies and the industries it investigates.

But Duffy said the public is right to say that crashes like the recent ones are unacceptable. That is why he plans to make sure “safety is paramount” as he leads the agency that regulates all modes of transportation.

“I feel really good about where we’re at and where we’re going and the plans we have in place to make sure we even make the system safer and more efficient than it is today,” Duffy said in the Fox interview.