The toll from Tuesday's terrorist attack at the Pentagon may be worse than initially thought. Some victims of the blast have started to arrive at Washington area hospitals, but more are expected.

Some 24,000 people work in the Pentagon. Initial reports soon after the terrorist attack said a hijacked American Airlines jet ploughed into the military complex that was under construction. If true, observers hoped few employees would be harmed.

Reports from the scene now say the section of the five-sided building struck by terrorists was indeed recently restored. But it's now back in use by Army, Navy and Marine Corps personnel, and heavily populated.

If confirmed, Dr. Christopher Wuerker of the Washington Hospital Center said there could be a lot of injuries.

"My understanding is they've got structural collapse. They've got major fires. In that setting, you're dealing with a large amount of crush injury burns," he said. "If there was an explosion that was associated with it, I don't know if there was but, if there was, then you have to deal with blast injuries. "

Washington Hospital Center is the region's largest trauma center. Shortly after the attack, it received seven Pentagon employees almost all of whom are suffering from second and third degree burns. Hospital officials say they've been told by rescuers on the scene on the scene at the Pentagon to expect up to 75 more patients.

The hospital center has postponed all elective procedures and admissions to make room for additional patients if necessary," explained Lisa Wyatt, a hospital spokeswoman. " The hospital center is on full emergency status. It is fully staffed to meet any additional needs."

More than 40 Pentagon employees were reportedly taken to other area hospitals. But that number could turn out to be small as well.