Patrick's Day frat party turned into chaos after a roof collapsed on top of dozens of revelers, injuring at least 16 people. Up to 500 students ... clad in bright green sitting on the shingled ...

It included a green roof sample measuring 0.71 m on 0.71 m, consisting of sedum vegetation blanket with up to 2 cm of organic matter, 2 cm of mineral substrate mix (lava, pumice, zeolite), and 4 ...