vlans and layer 3 routers/switches help

here's my problem, at my company we have a switch on each floor and each floor is it's own vlan. And from the documetations that was handed down to me, each switch on each floor is a layer 2 switch not layer 3. The layer 3 switch and router is downstairs in the basement with me. Inter-vlan routing is also enable in the company. Now today we had a switch that appeared to have gone down on the top floor (lights were still one, but solid and not flashing as an indication of activity) and everyone on that floor lost internet + network connectivity. What i can't explain is this, when the switch went down on the top floor i could now longer ping the default gateway for that vlan from another vlan.

I don't understand that, if each switch on each floor is a layer 2 and not layer 3 switch than the vlan Ip should be on the port/ports of the layer 3 switch or router downstairs in the basement. And the ping to the default gateway ip of that vlan should have gone through.

I asked the "consultant" that the company hired to solve this issue and he stated that  I can't ping the default gateway from any other vlan because the switch is down for that vlan.