his 50-year-old brother doug. the explosion caused varying degrees of damage to 350 homes. those closest to the plant are not allowed back into their homes. some of the families living further away are venturing back to assess the damage and to gather more of their belonging. they don't know when they'll be able to return for good because many homes are still without gas and power and parts of the city's water infrastructure were ripped apart. >> the water situation, if you live on the south side of town, the water you have, you can wash your clothes and hands, shower, just do not consume the water. >> the state fire marshal is leading the investigation into the cause of the fire that triggered the explosion. there are a number of other state and federal agencies at the explosion site including the epa and texas commission on environmental quality. last week we told you the last time osha regulators performed a full safety inspection at the west fertilizer company was nearly 28 years ago. last night we told you the plant