A Reddit video from the July 9 Fantasmic performance shows a pyrotechnic effect traveling from the lagoon toward the Disney's Hollywood Studios amphitheater crowd.
The original r/WaltDisneyWorld thread was posted under the title "Firework Shot Into Fantasmic Crowd Tonight (SFW)" by u/Pajamaetchi.
WDW News Today embedded the Reddit post and reported that eyewitness comments did not indicate a confirmed injury.
Original Reddit Video
Firework Shot Into Fantasmic Crowd Tonight (SFW)
by u/Pajamaetchi in r/WaltDisneyWorld
Direct Reddit post: https://www.reddit.com/r/WaltDisneyWorld/comments/1usa29s/firework_shot_into_fantasmic_crowd_tonight_sfw/
Fantasmic Uses Pyrotechnics
Fantasmic is a 30-minute nighttime show with water projections, live performers, character barges, lasers, and pyrotechnics.
The show runs in the outdoor amphitheater off Sunset Boulevard at Disney's Hollywood Studios.
Sources: r/WaltDisneyWorld thread by u/Pajamaetchi, WDW News Today, and Walt Disney World Fantasmic page.
Image credit: Walt Disney World.