(CNN) -- Events at a West Virginia air show were canceled for a second day Sunday after a crash a day earlier that killed a stunt pilot, show organizers said.
No one on the ground was injured in the crash Saturday.
Investigators with the National Transportation Safety Board arrived in Martinsburg on Sunday to begin piecing together what went wrong.
The crash occurred about five minutes into a planned 15-minute flight, said NTSB investigator Tim Monville.
"During one of the planned aerobatic maneuvers ... two opposing airplanes were to pass each other laterally," then pull up and perform a roll, Monville said. The plane that crashed "did not complete the maneuver."
Monville declined to identify the pilot.
CNN iReporter Jennifer Clark took pictures of the 2:30 p.m. ET crash, showing flames and black plumes of smoke rising from the ground.
"We saw a flash of light ... and heard the explosion sound," she told CNN's Don Lemon on Saturday. "It was scary."
"You just heard the whole crowd gasp simultaneously and everybody just kind of went silent and was just watching what was going on," she said.
Event organizers on Sunday urged those who witnessed the crash "to seek out support if they feel that viewing the accident traumatically affected them."
The West Virginia crash came one day after another deadly air crash.
A pilot lost control of his vintage plane during an air race in Reno, Nevada, on Friday, plummeting toward thousands of spectators before narrowly missing a grandstand and slamming into box seats. Nine people, including the pilot, died in that accident, according to local police.