On May 3, The Confederates resumed their attacks forcing Hooker's army to defend the river fords. This was the heaviest day of the fighting. Both wings of the Confederates attacked while their artillery concentrated on the Union line at Hazel Grove. The larger Union army held nearly all of the most strategic spots on the battlefield. Of these the key to the battle was Hazel Grove, a high open plateau that overlooked all the Union positions. Stuart realized this and early in the morning Confederates attacked up the slopes of Hazel Grove and captured about 100 men and four artillery pieces. For unknown reasons Hooker had ordered the artillery back from Hazel Grove. At the time of the attack, most of the artillery had already been removed. This was a costly mistake since the Confederate artillery could now fire down on the union positions with great ease. This finally forced the Union line back to a defensive position with his back to the river. Meanwhile, the other Union forces were advancing on Lee from the east. Lee split his army again and met and defeated the Federals near Salem Church (Fredericksburg). This was by far the bloodiest day of fighting. The fighting at Salem Church resulted in more casualties than the entire First Battle of Bull Run.