A nurse who had been treating the first patient to be diagnosed with and to die of Ebola within the U.S. has also contracted the virus and was diagnosed on Sunday, allegedly due to a breach in safety protocols.

The nurse, which has not been identified in public, had been treating Thomas Eric Duncan, a Liberian who was diagnosed with Ebola and had been receiving treatment at the Texas Health Presbyterian Hospital. Officials conjecture that there may have been an error in the way that she removed her protective gear, which then led to her also contracting the virus.

“The care of Ebola patients can be done safely, but it’s hard to do it safely,” said Dr. Thomas Frieden, the director of the Centers for Disease Control and Prevention (CDC). “Even a single, inadvertent innocent slip can result in contamination.”

Others have been pointing to a possible lack of proper training within the hospital as the cause of the spread.

Many hospitals “post something on a bulletin board referring workers and nurses to the CDC guidelines. That is not how you drill and practice and become an expert,” Bonnie Castillo, a disaster relief expert with National Nurses United, told Reuters.

“We have a system failure. That is what we have to correct,” Castillo said.

“We haven’t provided [doctors in the U.S.] with a national training program,” said Dr. Gavin Macgregor-Skinner, a public health preparedness expert at Pennsylvania State University, told Reuters. “We haven’t provided them with the necessary experts that have actually worked in hospitals with Ebola.”

Tom Skinner, a spokesman from the CDC, said that there are talks of having designated hospitals in each region that will specifically handle Ebola treatment, rather than having Ebola patients be admitted and treated at any nearby hospital.

The CDC will be holding a nationwide training conference call on Tuesday to prepare thousands of health care workers all over the nation in Ebola treatment.