The plane was supposed to leave Houston Intercontinental Airport bound for Lagos at 7pm. Airline officials tell us the plane was leaving the terminal when the air conditioning went out.
Passengers tell us they were forced to wait for hours.
"We were sitting down in the airplane for four hours. No air. I mean it was just steamy," said frustrated passenger Champs Bakare. "No air, no water, no food. Look at all these little kids."
United officials tell us by the time the AC was repaired, the flight crew would have been over hours by the time they landed in Lagos so they were forced to cancel. Passengers were given vouchers for hotels and meals and are expected to leave Houston at 11am.
Police were called out to deal with at least one angry passenger but no one was arrested.