the turret front. The M1 can be equipped with mine plow and mine roller attachments. Lessons from the war improved the tank's weapons sights and fire control unit. Waco siege During the Waco siege in 1993 two M1A1 Abrams tanks were deployed by the FBI against the Branch Davidians. Upgrades The M1A2 was a further improvement of the M1A1, with a commander's independent thermal viewer, weapon station, position navigation equipment, and a full set of controls and displays linked by a digital data bus. These upgrades also provided the M1A2 with an improved fire control system. The M1A2 System Enhancement Package (SEP) added digital maps, Force XXI Battle Command Brigade and Below (FBCB2) Linux communications system capabilities for commanders, and an improved cooling system to compensate for heat generated by the additional computer systems. The M1A2 SEP also serves as the basis for the M104 Wolverine heavy assault bridge. The M1A2 SEPv2 (version 2) added Common Remotely Operated Weapon Station (CROWS or CROWS II) support, color displays, better interfaces, a new operating system, better front and side armor, and an upgraded transmission for better durability. Further upgrades included depleted uranium armor for all variants, a system overhaul that returns all A1s to like-new condition (M1A1 AIM), a digital enhancement package for the A1 (M1A1D), and a commonality program to standardize parts between the U.S. Army and the Marine Corps (M1A1HC). Improvements to survivability, lethality, and protection have been sought since 2014. Iraq War Further combat was seen during 2003 when U.S. forces invaded Iraq and deposed Ba'athist Iraqi leader Saddam Hussein in the Iraq War's Operation Iraqi Freedom. Some crews were issued M136 AT4 shoulder-fired anti-tank weapons under the assumption that they might have to engage heavy armor in tight urban areas where the main gun could not be brought to bear. During the invasion, at least nine Abrams tanks were put out of action by fire from rocket-propelled grenades. One achievement of the M1A1s was the destruction of seven T-72s in a point-blank skirmish (less than ) near Mahmoudiyah, about south of Baghdad, with no U.S. losses. This was in the face of inadequately trained Iraqi tank crews, most of whom had not fired live ammunition in the previous year due to the sanctions then in operation and made no hits at point-blank range. Following lessons learned in Desert Storm, the Abrams and many other U.S. combat vehicles used