NEW YORK -- A second body has been recovered from near the scene of a huge explosion at a Staten Island oil storage facility.

Two workers died in the blast at the ExxonMobil depot. A third was badly burned and remains in critical condition.

"We fear the worst for them," New York Mayor Michael Bloomberg said during a news conference.

Bloomberg said the fire was the result of an industrial accident, which happened when a barge was unloading its cargo of gasoline at an ExxonMobil oil facility. A fiery column of black smoke could be seen for 30 miles.

Police say the investigation is in its early stages but officials are examining whether a malfunction in a pump might have caused the explosion.

The mayor said terrorism fears are unfounded.

"Right now, we know this is nothing more than a terrible industrial accident that may have taken the lives of two people," he said.

The three-alarm fire started at 10:10 a.m. EST, a spokeswoman for the Fire Department of New York said.

The explosion occurred at Port Mobile, near the Outerbridge Crossing in the southwestern part of Staten Island, said a spokeswoman for the Staten Island borough office.