Fire officials say a worker was injured in an explosion at a commercial building in West Duluth Monday afternoon. According to the Duluth Fire Department, it happened around 1:00 p.m. at 5805 Grand Avenue. The man was removing floor adhesive when the explosion happened. The building was undergoing renovations at the time, the fire department said. The explosion caused part of an external wall to collapse. The worker was seen at an area urgent care and released. The Duluth Fire Marshal's Office is investigating the incident.