After a balcony collapse at the Library Gardens apartment complex in Berkeley, CA killed six and injured seven others in June, the city has tightened building codes and began a forensic inspection into the balcony's construction. Lawsuits have since been filed against Segue Construction (the complex's builders and sub-contractors), Blackrock Investment (current Library Gardens owner) and Greystar (the complex's property management firm), among others involved in the building's construction.

The lawsuits, filed by the surviving victims and their families, allege that the balcony wasn't properly waterproofed:

The builder framed the balcony in Oct. 2005, but did not waterproof it right away. The next two months, the bare wood was exposed to more than 13 inches of rainfall. It was a wet winter.

The lawsuits say, that January, "These defendants consciously chose to waterproof and complete construction of the balcony for apartment 405, without correcting the water saturated wood components." And that the waterproofing locked in the moisture, creating "a concealed and hidden trap."

Between Oct. 2008 and summer of 2010, the lawsuits allege, "Tenants observed large mushrooms growing from multiple locations on the surface of the apartment's balcony, an unambiguous red flag warning that the wooden joists were rotting and that the balcony was at great risk for collapse."

The lawsuits say at least one tenant's complaint about the mushrooms is contained in a written document.

More on the lawsuit over at Berkeleyside. Get caught up on the tragic incident here:

• After deadly balcony collapse, Berkeley building and safety codes tighten
• Dry rot to blame for Berkeley balcony collapse; existing building codes called into question
• 6 dead after Berkeley balcony collapses