Needed expansion in laboratory floor space led to the opening of the Structural Components Laboratories in 1994. That year, the Northridge earthquake caused widespread damage to steel frame buildings, and the Powell Labs again lead in testing of methods to retrofit existing steel structures and methods of construction for new steel structures. The Structural Components Lab has a 9 m (30 ft) high by 19 m (62.3 ft) wide reaction wall which is 1.1 m (3.5 ft) thick. The total floor area is 14.3 m (47 ft) long by 21.3 (70 ft) wide and is a six cell box girder. The usable floor space in front of the reaction wall is 11.3 m (37 ft) long by 15 m (50 ft) wide. The total depth of the strong floor is approximately 4.25 m (14 ft) with a top slab 0.91 m (3 ft) thick and a uniaxial shake table 4.9 m (16 ft) long by 3 m (10 ft) wide. This shake table is recessed into the strong floor in front of the reaction wall.