(Photo by Holliday Moore - KJZZ)

Nurse John Roesler (in blue) is among 34 healthcare professionals being briefed before heading to Houston's MD Cancer Center to help.

When Hurricane Harvey rolled through Houston, it semi-submerged tens of thousands of homes in water. Among those living there when it hit were the health care providers who treat Houston's cancer patients.

While they sort through their own personal tragedies left in Harvey's wake, 34 nurses, technicians and other clinical professionals boarded a flight for Houston on Monday morning to help relieve their colleagues.

Sunday night, Banner Health MD Anderson's CEO Lamont Yoder held an emergency preparedness meeting with his Arizona team at their Gateway center in Gilbert.

Patients who were seeking care at the Houston hospital were placed on hold and their cases had to be prioritized.

Depending on individual cases some cancer treatments might require three or five days in a row, Yoder gave as an example.

"Some people maybe had their first or second day of that five days in a row and then that hurricane hit," he said.

For many patient cases in Houston, those treatments had to be placed on hold.

"Now, their cancer treatment has to be reassessed," Yoder said. "So, it's incredibly complex, because each treatment plan is unique and different."

Among those who stepped up to help was oncology and operating room nurse John Roesler.

"I know that a lot of treatments are behind," Roesler said.

He currently works at Banner Gateway Hospital's operating facilities, but he trained and worked at M.D. Anderson's Cancer Center five years ago and volunteered to help his friends now working in Houston.

"I know that the nurses living in the suburbs are trying to rebuild their lives," he said. "Whatever we can do to help reduce their strain is what we're after."

The crew plans to stay for at least a week. If the roles were reversed, Yoder said Houston would be here for Phoenix.