Thank you all for your sympathy...
ckcowl thank you for your suggestions. I did wash in cold water on delicate and I found the problem when the wash cycle stopped, that's what really had me baffled. I had used spray baste to secure the basting because it was so bulky and hard to handle. The tension I decreased but I didn't lengthen the stitches. Do you use a walking foot or open toe quilting foot? I'm a hand quilter by preference but charity quilts request machine quilting so I'm a newbie to machine quilting.