UPDATE 2: If you'd like to make a blood donation to aid the victims of this tragedy, please visit the Bonfils Blood Center web site.

UPDATE 1: According to Fox31's Eli Stokols, Holmes went to high school in San Diego, Calif., moved to Colorado to get a PhD in neuroscience at CU-Denver in the Fall of 2011, but dropped out just last month.

This morning we woke up to learn of a mass shooting at an Aurora movie theater, Century 16, that has left at least 12 dead and at least 50 injured, according to Aurora Police.  The gunman, 24-year old James Holmes, has been arrested.

FoxNews offers frightening eyewitness accounts of the shooting, which happened around 12:30 a.m. last night. According to moviegoers, Holmes entered through an emergency door, threw in a smoke bomb, and opened fire.  He was wearing a bulletproof vest and carrying a rifle and two handguns.

According to eyewitness, James Wilburn:

James Wilburn was sitting in the second row of theater 9 after midnight when an emergency door opened and a man entered, the Denver Post reports.

“He was dressed in black,” Wilburn told the newspaper. “Wearing a flack jacket and a gas mask.”

The man was carrying a shotgun and had a rifle strapped to his back, Wilburn said. The gunman then dropped a canister, causing a noxious gas to spew out. He raised the shotgun and repeatedly fired toward the back of the theater.

Wilburn and three friends dove to the floor, hiding behind seats in front of them. The gunman was only five or six feet away, he said.

Once the shotgun was empty, the gunman calmly dropped it to the floor, took the rifle and went on firing. Wilburn heard roughly 30 shots, the Denver Post reports.

The eyewitness accounts all convey frightening details about what transpired in the theater.  In addition to Holmes’ shooting spree, he also told police that there were explosives in his home.

Reports indicate that this is the worst mass shooting since the 2007 Virginia Tech massacre.  Our thoughts and prayers go out to all the victims and their families.