A small trash fire nearby startled visitors at the Las Vegas Healing Garden on the anniversary of the 1 October tragedy.
The fire happened around 8:30 Monday night near 4th Street and Colorado Avenue, according to Las Vegas Fire and Rescue Spokesman Tim Szymanski.
Police lined the street.
Szymanski says the bomb techs responded and they found no evidence of an explosion.
Witnesses say many were caught off guard.
"A lot of the people that had been survivors of Route 91, fell to the ground, started crying," said Jay Bryant-Chavez.
13 Action News also spoke with a man at a nearby motel at the time.
"I thought initially when I heard it it was a pipe bomb and I figured it had to do with the October 1st shooting," said Christopher Yoho.
It's unclear what caused the noise. Witnesses were relieved this was a relatively minor event.