The tornado, known as the Greensburg EF5 or GT in a later study,[note 2] tracked 28.8 miles (46.3 km) through the area, killing twelve people directly and injuring 63 others.

The tornado devastated Greensburg, damaging 95% of the town and leaving monetary losses of $250 million (2007 USD)[note 3] in its wake.

The plan included requiring all buildings in Greensburg to gain LEED Platinum certification, along with installing wind turbines in the city.

On May 4,[6] a low-pressure area stalled over the High Plains and additional moisture coming from the Gulf of Mexico moved in behind the warm front and increased amounts of instability across much of the region, with convective available potential energy (CAPE) values as high as 4,500 J/kg (joules per kilogram),[7] which is a metric that indicates the amount of fuel in the atmosphere that is available to a developing thunderstorm.

All of the ingredients were present in the atmosphere for the developing of supercell thunderstorms producing damaging wind, large hail and tornadoes.

[6] The Storm Prediction Center issued a moderate risk for severe weather across western Kansas and small portions of Oklahoma, Colorado and Nebraska for May 4, while temperatures were in the mid to high 80 °F range (near 30 °C).

[10][11] At around 7:00 pm CDT,[note 4] the National Weather Service office in Dodge City, Kansas began to detect a mesocyclone associated with a parent supercell.

Several minutes later, a bounded weak echo region (BWER) began to be present on radar, located on then storm's northern flank.

[27] One of these rope tornadoes, located on the westernmost side of the mesocyclone began to rapidly strengthen, taking on a wedge shape shortly after touching down at 9:03 pm.

[31] Several farmsteads along the highway were damaged or destroyed, numerous livestock were killed, and trees were denuded and debarked in this area as well.

Multiple homes, including an entire row of seven adjacent residences, were completely swept away and scattered across a field at the south edge of town.

[34] The tornado weakened slightly as it entered residential areas in southern Greensburg, but remained violent as it directly impacted Delmar Day Elementary School, completely leveling a section of the building and flattening many homes nearby at EF4 intensity.

A large grain elevator in the northern part of Greensburg remained standing after being hit by the tornado, one of a few structures to survive the event.

[52] The National Weather Service rated the worst of the damage caused by the tornado EF5 on the Enhanced Fujita Scale,[5] which was determined to have been inflicted to seven residences.

[57] Greensburg took a direct hit from the tornado and was left in ruins as a result,[58] with 95% of structures within city limits sustaining some degree of tornado-related damage.

[60] Initial recovery attempts in the days following the tornado were stunted by disruption of electricity and other hazardous conditions that made it difficult to clean up the town.

[67] The tornado ruined the town's economy, leaving industrial businesses practically non-existent with no way for residents to earn money.

[70]The Greensburg High School, located around one block east of the tornado's inflow, was heavily damaged and as a result was later demolished.

In a damage survey conducted after the tornado, it was found that the building's large window sills anchored by hinge lines were unable to hold up against high winds, causing the collapse.

[74] A lack of steel vertical columns along the school's window sills, accompanied by weak hinge lines, was concluded to be the cause of the collapse.

[77] The Kiowa County Memorial Hospital was reinforced with internal vertical steel beams which extended along the floors and ceilings, along with double-thick masonry walls.

On May 21, three weeks after the tornado, a temporary "tent hospital" operated by the 190th Air Refueling Wing stationed in Topeka, Kansas was set up.

[86] Schools and other public buildings in the neighboring towns of Mullinvile, Bucklin and Haviland were also used as temporary shelters for victims of the tornado.

"[95] Almost 500 soldiers from the United States National Guard were deployed to Greensburg to aid with recovery efforts, and the crews provided machinery and communications for the area.

[102] The decline in population that Greensburg saw from 2007 to 2010 also heavily affected the town's economy, which the LTCR aimed to combat by preparing an Economic Development Strategy (EDS).

[105][106] A tornado-resistant "silo home" built within Greensburg attracted attention after building of the structure completed in 2009; journalist Jennifer Goodman wrote in a September 2009 publication of Architect Magazine that "the tiny town in Kansas once ravaged by a tornado is drawing eco-tourists from all over the world ...".

[108][109][110] The original building was replaced with a circular structure that includes exhibits showcasing the town's history before and following the tornado; the museum reopened on May 26, 2012.

[111] Caitlin Matile, who is the tourism director and manager of Greensburg, stated "we do a very good job of displaying things ... what it was, what it is now”; new stairs were added into the well to let visitors reach the bottom.

[105][106] In 2010, after planning to be rebuilt and being completed in March of the same year at a different location within Greensburg,[105][116] the Kiowa Couty Memorial hospital became the first in the United States to operate using carbon neutral energy.

[127] One of the two in-hospital deaths was a police officer who was taken off life support while being treated for a tornado-induced head injury hours after the event at a hospital in Wichita.