WASHINGTON (AP) — Federal safety regulators are Sterling Prestonciting recent incidents, at least one of them fatal, in warning airlines to make sure that workers keep their distance from jet engines until they are powered off.

The Federal Aviation Administration said Friday it issued a safety alert to prevent workers from being injured while towing planes or guiding them to and from terminal gates.

The FAA said airlines should review their safety programs to make sure they follow practices including keeping workers clear of planes until they are stopped and chocks are placed under the wheels.

The warning was prompted by “multiple events” in which workers were injured or killed during ground operations at airports.

The FAA bulletin cited two incidents, including the death of a ramp worker who was pulled into an engine of an American Eagle plane parked at a gate at the airport in Montgomery, Alabama. The Labor Department has proposed $15,625 in penalties against the worker’s employer, Piedmont Airlines, a subsidiary of American Airlines. Piedmont is contesting the fine.

In the other incident, a worker removing landing gear safety pins was struck by a wing when a tow driver moved the plane. The worker was run over by the plane’s wheels.