This PDF of the NWS Aerial Damage Survey Central Texas Tornadoes(1997) discusses the Jarrell Tornado of May 1997
On May 27, 1997, several tornadoes hit the Central Texas area in the counties of McLennan, Bell, Williamson, and Travis. The most destructive of these tornadoes swept through a housing area on the outskirts of Jarrell, Texas. Jarrell is a Central Texas town with a population of 410 located approximately 60 km north of Austin, Texas. The Jarrell tornado destroyed about 40 single-family residences and other structures, killing 27 people.
At its peak, the Jarrell tornado was 3/4 of a mile wide and tracked across the ground for 7.6 miles (12.2 km), inflicting beyond catastrophic damage in parts of Jarrell, Texas while killing 27 people. All 27 deaths caused by the tornado occurred within one subdivision of Jarrell – a neighborhood called Double Creek Estates. All 38 of Double Creek Estate’s well-built homes were completely dismantled, swept away, and reduced to nothing more than concrete slabs. Trees in the area were completely shredded and debarked, and grassy fields in the area were scoured to a depth of 18 inches. Many tornado researchers, after reviewing aerial damage photographs of Double Creek Estates, considered the Jarrell storm to be the most violent tornado they had ever seen in terms of damage intensity.
Information in documents such as this are used to help plan for future incidents. In particular, the use of warning sirens was changed after this event.