MOORE, Okla. - The Oklahoma Insurance Department says a preliminary estimate suggests the cost of the tornado that hit the Oklahoma City suburb of Moore could exceed $2 billion.

Spokeswoman Calley Herth tells The Associated Press that the early tally of damages is based on visual assessments of an extensive damage zone stretching more than 17 miles and the fact that the tornado was on the ground for 40 minutes.

She says the monetary damage caused by Monday's twister could be greater than the $2 billion in damage from the 2011 tornado that struck Joplin, Mo., which left a smaller, three-mile trail of destruction.

The head of the Federal Emergency Management Agency (FEMA) says U.S. officials are "going neighborhood to neighborhood" to make sure victims get the help they need.

Residents are meanwhile returning to where their homes once stood, and beginning to pick up the pieces to start over. Despite the tragedy, stories of survival and compassion are shining through, and many are being hailed as heroes for helping save lives.

The National Weather Service says the twister was one of the strongest ever to strike in the U.S., with winds topping 200 miles per hour. An estimated 2,400 homes were damaged, directly impacting nearly 10,000 people.

At least 24 were killed, down from an initial reporting of 51.

AP wire services contributed to this report.