Mattoon and Charleston fire crews responded to two working structure fires on Monday. Crews arrived to the fires off of Lake Land Boulevard just before 4:30 a.m. Mattoon Fire Chief says, when crews got to the scene they saw smoke and flames coming from the building. Flames were showing from a north apartment complex and smoke was showing from the southwest apartment complex. Multiple fire crews were called out to the scene. Officials say this is the second time they've responded to at fire at this building this month. Officials put up crime scene tape around the structure. The Matton Fire Chief said it could be a "criminal investigation."