Salvatore "Rico" Sanchez, a preventive dentistry specialist, was treating a patient at Fort Hood's Soldier Readiness Processing Center Thursday afternoon when he heard screams. He thought it was rowdy co-workers at first. Then he saw a man enter the building with blood on his uniform.
Nearby, a graduation was unfolding for soldiers who had missed their graduation ceremonies. After the shots rang out, everyone was herded into the processing center for shelter.
The clinic was soon filled with wounded men and women, some in uniform, others in cap and gown.
"There was blood everywhere," Sanchez told ABC News Thursday. "There was a lot of confusion."
He and others sprang into action, attending to the wounded, fetching water and gauze and, most importantly, keeping the victims awake until the paramedics arrived.
The injuries ran from non-life-threatening to near lethal. A 19-year-old female soldier from Milwaukee had been shot in the stomach. Another soldier from Grand Rapids, Mich., had been shot in the arm. An Army reservist from Topeka, Kan., who was at the Texas Army base to work with soldiers suffering from wartime stress, had been shot in the left shoulder.
The man with blood on his uniform had been only a witness to the violence. He told Sanchez that he initially believed the shooter, who was dressed in uniform, was shooting blanks.
"He said that it was only when he saw the blood that he realized what had actually happened," Sanchez said.
There was chaos and confusion everywhere. The building was soon locked down, and a soldier was posted at each door to prevent anyone from entering.
No one was allowed to use a cell phone or text message. When Sanchez had a spare moment, he ran to his computer and sent out some messages on Twitter, where he goes by the name "Rico Rossi." He wanted people to know he was OK, and he wanted to get the news out to the public.
His tweets give an insight into the timeline of when things unfolded and when the lockdowns occurred, calling attention to the slow trickle of information:
"if your OFFPOST right now dont come to base, multiple shootings, several casualties, possible terrorist suspects ... FT HOOD TX"
"a soldier i treated here said he was waiting in line @ SRP [the Soldier Readiness Processing Center] when another soldier stood up and started shooting."
"wow..... umm the entire FORT HOOD just restricted all CELL PHONE usage, unless its govt authorized... twolla @ me yall..."
"GET OUT OF HERE!!!!! there were children in the theatre!!! thank God they're fine!! We have them here in the clinic."
"Army post is a mess right now, lots of traffic ... everyone in a hurry to get off post and pick up their kids or get home to their loved ones"
At midnight, Sanchez described himself as "tired and dehydrated."
With the exception of emergencies, his superiors have ordered that all dental appointments be rescheduled on Friday.
Fort Hood's Soldier Readiness Processing Center is where people go to receive vaccinations, get their teeth checked or update their records before shipping out. Soldiers returning from active duty pass through the center to drop off their bags and get some rest.
"The SRP is the last place a person should get shot," Sanchez said.
There are strict rules and regulations for carrying weapons on base. Discharging a weapon can result in serious disciplinary action.