The Rockford Department of Public Safety reports that an explosion that occurred at the Harvest Hill apartments, 100 Childsdale NE, last Friday, November 26, was caused by a resident cooking marijuana butter.

Police said that butane lighter fluid used in the cooking process was ignited when the resident lit a cigarette while cooking the marijuana butter in the bathroom.

The injured resident is at Spectrum Health Butterworth Campus recovering from burns he received in the explosion. Rockford investigators declined to name the resident, pending the outcome of their criminal investigation into the explosion.

Inspectors felt at the time of the explosion that there might be significant damage to the building, which has eight separate units. Rockford DPS investigators met with structural engineers on Monday, November 30, and determined that the structure was safe. Residents, who had been displaced since Friday, were notified they could return home.

Police said that damage estimates for the property are not available.