A video of a staircase used by thousands to get to and from Rio's Maracana stadium shows the structure wobbling unnervingly as spectators left the World Cup game between Argentina and Bosnia on Sunday.
The structure, built on scaffolding, can be seen swaying as fans grab a shaking hand rail. The stairs are the only exit leading to the subway.
Fans told The Associated Press that they were scared it could come crashing down.
"When people walk on it the wood moves, so with thousands of people walking up there, there could be an accident," Jorge Martinez, a Mexican systems engineer who used the stairs Sunday night, told the AP.
The video was shot by Paula Kossatz, a Brazilian who was recording protests outside the stadium during the game.
AP reported that the Rio de Janeiro state government issued a statement saying that the stairs were inspected and reinforced, then re-inspected Tuesday for safety.
On the other side of the stadium, a VIP entrance is built of concrete.
FIFA and local authorities have disagreed over who should take responsibility for temporary structures like the staircase, says Wyre Davies of the BBC. In a video report, Davies gives an unsteady hand rail an easy shake and tips a loose stair tread with his foot.
"All along there've been concerns about the safety and the integrity of temporary structures," he says. "It all seems to have been put together in something of a hurry."
The next game at Maracana is Wednesday at 4 p.m. ET between Chile and Spain.