Many of the 1,374 drones seemed to be confused, marring Tuesday’s high-tech light show celebrating Chinese Labor Day and turning some of the images into a glittering mess in the sky.

An Ehang drone manufacturer affiliate known as Egret put on an elaborate Labor Day show, creating images over 850 feet tall, using drones bedecked with brilliant lights. The number of drones in the sky was an homage to the Xi’an city wall from which they were launched that stretches 13.74 kilometers.

Before the show, Ehang Egret CEO Shi Zheyuan warned Chinanews of potential malfunctions that could arise, if spectators’ mobile devices interfered with the signals. Just one drone slipping from formation could — and did — result in aerial disarray.

Ehang Egret also had a difficult time recovering the wayward drones. Some of the heavier ones simply dropped out of the sky. The company is preparing an official statement on the show, which cost the city of Xi’an $1.7 million.

The performance may have proven disheartening for the company, which hopes to profit from flying taxis in the near future. They claim to have completed over 1,000 flight tests.