The urgent call came in: Roadside bombs had ripped through two Humvees and wounded eight or nine U.S. soldiers.

Medevac helicopters immediately hit the air to ferry the soldiers to the main U.S. military hospital. But when they arrived, they carried only five patients.

The other four were dead.

With 2009 expected to be the bloodiest year since the U.S. invaded Afghanistan, medical personnel at Bagram's SSG Heath N. Craig Joint Theater Hospital say they've already seen an increase in casualties and expect more. The flow of dead and wounded puts enormous strain on the soldiers and the medical staff who must face it head on.

"Everything I've experienced is boredom or terror," said Air Force Maj. Adrian Stull, a 36-year-old emergency physician from Beavercreek, Ohio. "And if I have to choose between the two, I'd have to choose boredom, because everyone goes home with all their fingers."

June 1 was a day of terror.

It started when two roadside bombs hit the same convoy of 10th Mountain Division soldiers only a couple of miles apart in Wardak, a province west of Kabul. The damage was so severe that one of the Humvees split in half.

By the time the helicopters arrived, four men were already dead. Their comrades loaded them into body bags, tense with anger and grief.

In the meantime, the emergency room prepared to move from zero to a thousand miles per hour — "organized chaos," as medical Tech Sgt. Carol Granger put it.

Then the stretchers arrived.

Three of the soldiers had open fractures in their legs, raw and bleeding. The one being treated by Air Force Capt. Shannan Corbin was in his early 20s, with open leg wounds, dental contusions and a bleeding head.

Wounds from blasts and explosive devices are considered the hallmark injuries of the Afghan war. Because armor covers the body's core, injuries to arms and legs are common.

As the medics worked, with the American flag in the background, they sweated. The heat was turned up because critically injured patients cannot regulate their own body temperatures.

A soldier screamed, so loudly that emergency room physician Capt. Travis Taylor couldn't tune it out. The soldier, who had an open fracture, had just learned one of his buddies was killed.

"That one was tough," Taylor said. "He was really screaming, and it snapped me out of my focus on the patient I was with."

Another soldier, Pfc. Anthony Vandegrift, had broken both legs. His left eye was swollen shut. The two soldiers in the front of his Humvee were killed, along with the gunner who had been standing halfway out the top.

He called his father while still on the emergency room table.

"I said, 'Hey dad, remember how you told me not to join the infantry? Well, I don't regret it, but I got blown up,'" Vandegrift, of Mililani, Hawaii, said.

Recalling the blast, he said it was "like a video game almost."

"You're going along and everything goes black. I could hear everything but I couldn't see everything," Vandegrift said. "Everything went black and I just remember 'boom.' Not sure if I passed out or not, but when I was able to move around I was upside down. My chunk of the Humvee was blown off from the rest."

Doctors at Bagram say there is nowhere in the world — except other war zones — where physicians face such severe wounds day after day. That constant stream takes a toll.

Granger, who is stationed at Offutt Air Force Base in Nebraska, said she tries not to personalize her work.

"We have to process it later on, but at the time you have a job to do. We've seen a lot ... and I hope we can handle it when the time comes," she said.

Corbin says home bases try to prepare the medical staff "mentally, emotionally and spiritually" for the deployment, but she's not sure it works.

"You can see pictures. You can hear people talk, but I don't know that anything really prepares you," said the 39-year-old nurse from Biloxi, Miss. "We hope emotionally and mentally that it's just another string of events. But I don't know how we can walk away from this as just another string of events."

In the intensive care ward nearby, Vandegrift lay beside the one other soldier in his Humvee who survived. The soldier may be paralyzed.

Holding a guitar, Vandegrift strummed a song for his friend: "The Star-Spangled Banner."