A fire has destroyed one of two memorials at the site where 18-year-old Michael Brown was killed by a police officer in Ferguson, Missouri.

Ferguson resident Meldon Moffitt said the fire started around 6:30 a.m. Tuesday on Canfield Drive, the street where Brown was fatally shot Aug. 9 by Ferguson police office Darren Wilson.

About two dozen residents gathered at the site Tuesday morning, many of them angry. One man said it was like a grave being desecrated.

Ferguson police spokesman Devin James says the cause of the fire is under investigation.

Brown's death led to several days of protests and unrest in Ferguson, a St. Louis suburb. Investigations into the shooting by a state grand jury and the U.S. Department of Justice are ongoing.