The Federal Emergency Management Agency (FEMA) is denying an appeal for funds to rebuild West, Texas, the site of the April 17 explosion at a fertilizer plant that killed 15 people and destroyed some 150 buildings.

In a letter to Texas Gov. Rick Perry (R), FEMA says the impact from the explosion "is not of the severity and magnitude that warrants a major disaster declaration."

FEMA workers have been on the ground in West since the blast occurred in April, assisting with initial aid, like debris removal and shelter for those who lost their homes. The agency has already been authorized to cover 75 percent of costs incurred by the local governments responding to the explosion.

West had requested $57 million to cover repair and rebuilding costs, including $40 million to rebuild West Middle School, a neighboring building that was leveled in the blast.

In a statement Wednesday, FEMA noted it had provided immediate and continuing financial assistance in the aftermath of the explosion.

"775 individuals have registered with FEMA for assistance, and FEMA and the SBA have provided more than $7 million in direct federal disaster assistance grants and low-interest disaster loans for eligible individuals and families," said FEMA spokesman Dan Watson in a statement.

FEMA also said they continued to work to reimburse costs related to debris removal and emergency protective measures.

The agency also noted that by law, they were prohibited from duplicating costs handled by private insurers.

Texas can appeal the decision within 30 days.

Officials in the town had been aware that the agency might not fund the full 100 percent of disaster relief. That decision is based on both damage to public property and the size of the state in which the disaster occurred. 

FEMA likely denied the funding appeal because much of the damage in the West explosion was to private property presumed to be insured and because Texas, among the nation's most populous states, is presumed to have state-level resources.

At a funeral service for the first responders who died responding to the fire that eventually caused the explosion, President Obama pledged the support of the federal government would continue "even after the cameras leave."

"To the families and neighbors grappling with unbearable loss — you are not alone. You are not forgotten," Obama said.

This story was updated at 2:04 p.m.