From the article, the posted weight limit was 26 tons. A quick google search ("bus weight") shows that buses can easily exceed that limit and the bus on the bridge was a "double" bus.
Maybe the bus wasn't supposed to cross that bridge?
Maybe the bus wasn't supposed to cross that bridge?
The bridge was 136m long, by about 13m wide and assuming 2.5cm of water content:
136m * 13m * .025m = 44 m^3 of water, or 44,000 kg, roughly 50 US tons.
A newspaper report said there was a light snow with 1 or 2 inches accumulated since 2am the morning of the collapse. Photos of the scene showed grass and small rocks on the ground visible through the snow, so it doesn't seem like there was a lot of snow on the ground. Even if there was heavy snow a couple days before the collapse, most of it would have been plowed off, I don't see big berms of snow on pictures of the collapse.
So if there was just a couple inches of snow, then it was probably closer to 10 tons worth of snow.
https://www.cnn.com/2022/01/28/us/pittsburgh-bridge-collapse...
10 lb/ft * 450ft * 45ft / 2000 = ~100 tons