Texting by the pilot of a medical helicopter contributed to a crash near Mosby, Mo. that killed four people, federal accident investigators declared Tuesday.

The board also approved a safety alert cautioning all pilots against using cellphones or other distracting devices during critical operations.

It was the first fatal commercial aircraft accident investigated by the National Transportation Safety Board in which texting has been implicated.

And it underscored the board’s worries that distractions from electronic devices are a growing factor in incidents across all modes of transportation — planes, trains, cars, trucks and even ships.

The five-member board unanimously agreed that the helicopter crash was caused by a distracted and tired pilot who skipped preflight safety checks, which would have revealed his helicopter was low on fuel, and then, after he discovered his situation, decided to proceed with the fatal last leg of the flight.

The case “juxtaposes old issues of pilot decision making with a 21st century twist: distractions from portable electronic devices,” said board Chairman Deborah Hersman.

NTSB documents show the pilot James Freudenberg made and received several text messages during the time the helicopter was being prepared for takeoff and leading up to the time it crashed outside of Mosby. Freudenberg, along with flight nurse, flight paramedic, and a patient, were killed when the helicopter crashed.

Lack of fuel was listed as a contributing factor to the crash.

Freudenburg, Randy Bever and Christopher Frakes of LifeNet, and patient Terry Tacoronte were killed in the crash.