The plane took off at 1505 PST on a local VFR pleasure flight with 4 occupants and about 48 gallons of fuel on board. The plane was estimated to be about 140 lbs over the maximum gross weight limit. At about 1622 PST, it was observed to break up in flight. Several witnesses reported the plane diving out of a cloud. Most reported hearing some type of explosive sound, and many also reported hearing a high-pitch whining/screaming/revving sound just before or after breakup. The plane was estimated to still be about 63 lbs over the maximum weight limit when it broke up. The wreckage was found scattered over an area of more than 1000 ft. The horizontal stabilators and vertical stabilizer had failed in their root areas and separated. The right stabilator had a downward spanwise camber. Both wings separated from the fuselage with the outboard 4 ft also separating. The leading edges of the right and left inboard wing sections were damaged and molded in a manner that one closely matched the other.