My gasoline just started pouring out from underneath my van. What coul

The fuel line at either the O-rings between couplings have worn out and letting fuel around it, or one of the flexible fuel line (most made of rubber material) have have failed for whatever reason and allow fuel to spill out.

The cause of this could be high temperature deteriorating the rubber lines, wrong material of the O-rings & flex fuel lines which certain types of fuel additives could cause deteriorating of the material, improper connection of the fuel line which cause the fuel connection to fail.

You should bring it to the dealer or reputable auto mechanic that has access to Technical Service Bulletins (TSB) which are reports to US Department of Transportation by the auto manufacture for all recalls & repairs to check this problem out since it could be part of a bigger recall which is a free repair even though the vehicle is out of warranty.