I now pay mortgage on my deceased father's house. Are my sibllings entitled to anything since there is no will.

Dying without a will is called dying intestate and Delaware's intestate succession laws determine to whom your father's assets go.  If there is a surviving spouse, she is first in line to get any assets, but what she gets is limited by certain circumstances.  If you and your siblings are the survivor's children, she gets the first $50K, plus 1/2 the balance of the estate plus a life estate in any real estate.  The children get the rest.  If the children have a different mother, (or some do), the surviving spouse gets 1/2 of the estate plus a life estate in the real property. Balance goes to the children.  If there is no surviving spouse, the assets (including real estate) go to the surviving children to share equally.  Depending on your situation, if there is no surviving spouse, for example, you and your siblings would share the house and also share in paying the expenses for its upkeep, including the mortgage.