MOORE — The deadly EF5 tornado that struck the south Oklahoma City area Monday pitched 10-ton propane tank a quarter mile from an elementary school at its strongest point, officials with the National Weather Service in Norman said.
Damage teams sent by the weather service determined the twister was strongest at Briarwood Elementary School, which was destroyed, said weather service meteorologist Jonathan Kurtz. The weather service on Friday released a preliminary report that detailed the strength, length and path of eight tornadoes Sunday and Monday in Oklahoma.
Teams assessed the damage on the ground and with the aid of global positioning software to determine the strength of each tornado based on the Enhanced Fujita scale. The scale rates tornadoes based on the damage they cause and includes six categories, from EF0 to EF5. Wind speeds are determined based on damage estimates, Kurtz said. The wind speeds range from 65 mph to over 200 mph.
The strongest and deadliest tornado in the outbreak did the worst damage at Briarwood in south Oklahoma City.The tornado formed about 2:45 p.m. in the Newcastle area and tracked northeast along Interstate 44 before cutting a direct path through Oklahoma City and Moore.
It stretched 1.3 miles wide at its largest and traveled 17 miles.
On the ground for 50 minutes, the EF5 tornado killed 24, including seven children who died inside Plaza Towers Elementary, two infants and a 4-year old. All children at Briarwood survived, despite the tornado ripping off the roof and crumbling the building's innermost walls, reducing it to rubble, Kurtz said.
An EF5 tornado includes wind speeds of more than 200 mph, Kurtz said.
The day before the tornado hit Moore, another one claimed the lives of two men in the Shawnee area and flattened a mobile home community in Bethel Acres. That twister formed around Lake Thunderbird about 6 p.m. and moved 20 miles northeast toward Shawnee. The weather service has estimated it to be an EF4, a category that places wind speed estimates between 166 and 200 mph.
A lethal record
According to the weather service, the Monday twister that took two dozen lives in Moore was the ninth deadliest in state history.
The most deadly tornado of all time in the state killed 116 people on April 9, 1947, in Woodward, weather service records show.
The May 3, 1999, tornado killed 44 and is the state's sixth deadliest on record.
Seven EF5 twisters have struck Oklahoma since 1950, the time researchers established climatology for tornadoes, Kurtz said.
On Sunday, an EF3 tornado that ran near the tiny town of Carney in Lincoln County stretched for 20 miles, with estimated wind speeds reaching 165 mph.
Other tornadoes reported by the weather service included:
• A 7-mile, eight-minute EF1 twister that hit Edmond about 4:20 p.m. Sunday.
• A small EF0 tornado ran for less than a mile about 4:30 p.m. Sunday in the Arcadia area.
• Two tornadoes, an EF2 and EF1, hit the Prague area between 7 and 7:30 p.m. Sunday.
• A tornado struck the Marlow area Monday. Its strength is not yet determined.
The weather service continues to investigate to determine if more tornadoes hit the state Sunday to Monday, Kurtz said.