Smith was the dominant reliever of his era and still sits behind Trevor Hoffman and Mariano Rivera, two sure-fire Hallof Famers, for third all-time in saves with 478.
He told the inquest at Lambeth Town Hall he was working near London Bridge on the day of the fire and found out about the blaze when his wife rang him just before 16.30 BST.
Hundreds of soldiers, police and plainclothes security officer equipped with fire extinguishers and anti-explosive blankets ringed the Great Hallof the People and the adjacent Tiananmen Square for the opening session.
The central questions for the inquest at Lambeth Town Hall to address will be to find out why six residents perished in flats away from the original seat of the fire in flat 65 and how did it spread so widely.