In the Battle of Badr, he decided to stay behind while other veterans joined the army to fight the Prophet (s.a.w.).  He was anxious of the outcome of the battle and would ask anyone who would come from the vicinity of Madina if he had any news.  At last when Abu Sufyan returned, crest fallen and ashamed, Abu Lahab inquired: "Tell me what happened, for no doubt you have the reliable news."

        Abu Sufyan related how his army of Meccans suffered a shameful defeat, and how the great veterans of Quraish fell, one after the other.  "Believe me, it was an effortless surrender.  We seemed to be at their command, submitting our necks for slaughter and our hands for being taken prisoners.  And I do not blame the Quraish.  By God! We saw white robed soldiers on black horses fill the place, and none of us could stand against their onslaught."

        Abu Lahab was overtaken by grief; he began to cry and wail.  Sitting next to him was a slave called Abu Rafe' who was known for leaning towards Islam.  In a fit of uncontrolled anger, Abu Lahab slapped him on the face; and then there was a commotion in which a lady, Ummul Fadhl, hit Abu Lahab on his head.

        Abu Lahab entered his house, bitter and humiliated; and within 7 days thereafter, died a miserable death.
 

Reference:
Pearls of Wisdom.  A String of Incidents in the History of Islam.  The World Federation of Khoja Shia Ithna-Asheri Muslim Communities. Page 26.