Michigan State Police, in connection with several federal, county and metro Detroit agencies, executed 22 search warrants in southeast Michigan in connection with marijuana trafficking.
Police said the raids took place at a mix of private businesses, homes and four warehouses -- in Wayne, Oakland, Washtenaw and Jackson counties.
Workers at four Detroit warehouses were on the job when police came calling. That knock on one door, according to neighbors, included an explosive device.
Police targeted 18 other locations all accused of processing pot for distribution.
"They were very sophisticated they had brought in materials to build actual little greenhouses inside, I guess you would say inside the warehouses. They had their own water supply and electricity and grow lights," said Lt. Michael Shaw from the Michigan State Police.
At a location near 7 Mile and John R police brought out at least 25 distribution boxes which sent electricity to grow lights.
MSP seized more than 500 marijuana plants, a large quantity of processed marijuana, several weapons and took several individuals into custody.
"We've arrested quite a few people and until we get them arraigned we don't want to discuss any specific numbers," said Shaw.
State police say the blast may be linked to butane which is used to make an ingestible form of marijuana.
MSP's investigations were helped by the ATF, FBI, ATF Combined Violent Reduction Partership, Washtenaw County Sheriff Department, Livonia Police Department, Northville Township Police Department, Canton Township Department of Public Safety, Plymouth Township Police Department, Western Wayne Special Operations Team and the Michigan State Police Emergency Support Team.