If denominators in LINE/LINE are 0 then you divide by zero.

[Czapa10]

You should return false if the denominators are zero.

btw You can optimize this function by a lot. Denominators for uA and uB are exactly the same so you should compute the denominator once and save it to a variable. Then you can reuse the variable for both uA and uB.
Also certain subtractions is you algorithm are done twice.
This is my C++ version:

fn Intersect
(line Line1, line Line2)
{
    v2 A = Line1.Start;
    v2 B = Line1.End;
    v2 C = Line2.Start;
    v2 D = Line2.End;
    
    v2 BA = B - A;
    v2 DC = D - C;
    v2 AC = A - C;
    
    f32 Denominator = DC.Y*BA.X - DC.X*BA.Y;
    if(Denominator == 0)
        return false;
    
    f32 U1 = (DC.X*AC.Y - DC.Y*AC.X) / Denominator; 
    f32 U2 = (BA.X*AC.Y - BA.Y*AC.X) / Denominator;
    
    return U1 >= 0 && U1 <= 1 && U2 >= 0 && U2 <= 1;
}