That pic(and others) don't make sense. Why is there none on rooftops or car rooftops? Why are cars buried in it, yet the people are walking on top of it?
Did you notice all the people in short sleeves. The weather is hot in Jalisco!
According to the newspaper the hail happened early in the morning and then the temperature shot up into the 80s and it all started to melt away.
This caused flooding throughout the city as the storm drains backed up.
That building on the left side collapsed from the weight of the hail on roof, and then it all just slid off and melted.