Amazon will restart drone deliveries in Arizona after two Prime Air drones struck a crane in Tolleson.

Amazon says it will restart drone deliveries in Arizona just days after two of its Prime Air aircraft collided with a crane in Tolleson, west of Phoenix. The crash occurred Wednesday afternoon when two MK30 drones struck the boom of a stationary construction crane near an Amazon warehouse. Both drones sustained "substantial" damage, according to a preliminary report from the Federal Aviation Administration.

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The FAA and the National Transportation Safety Board have opened investigations into the incident. One person at the scene was evaluated for possible smoke inhalation, Tolleson police said.

Amazon temporarily paused drone operations in Tolleson but announced it will resume flights on Friday after conducting an internal review. The company said it found no fault with the drones or supporting systems but will introduce "enhanced visual landscape inspections" to better monitor for obstacles such as cranes.

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For Amazon, the crash is the latest challenge in a drone program that has faced delays, technical setbacks, and regulatory scrutiny. Prime Air is currently available in just a handful of U.S. cities, though Amazon has set a goal of delivering 500 million packages by drone annually by the end of the decade.

Drone delivery remains a wider industry experiment. Walmart, for example, has expanded its partnership with Wing to launch drone services in several U.S. cities, while Target is also testing deliveries with Wing in metropolitan areas.

Drone delivery is still an experimental frontier. Walmart has expanded its partnership with Wing to roll out drone service in cities like Atlanta, Houston, and Orlando. Meanwhile, Amazon is pushing ahead with Prime Air to deliver items in less than an hour.