Electrical house fire!

I need any help or suggestions. House caught fire , noticed the ground wire is sticking out of the ground and think it was cut by lawn mower. Lights flickered, then cut off and house caught fire. My landlord sends over some type of generic electrician and he can't get power to certain rooms in the house .He twisted the ground wire back together. Do we need a whole new power box or just maybe new wiring in some parts? I have no clue..