A young intern with just four weeks on the job said he thought he was going to die Thursday when a gunman opened fire in the Capital Gazette newsroom.

“In that moment, I thought I was going to die. I thought we were going to die,” said Anthony Messenger, who ran and hid under a desk with a colleague as soon as they heard shots ringing out in the Maryland office.

Messenger, a sports intern at the local newspaper, recalled the harrowing ordeal on NBC’s “Today” show that left five of his colleagues dead and several others injured.

“That’s never something that crossed my mind when I took the internship, that I might see people die, people that were nothing but welcoming and comforting to me,” he said. “They were accommodating to me and they were trying to help me write the best stories I could.”

Messenger and his co-worker Selene San Felice first ran toward a door to escape suspected gunman Jarrod Ramos, 38, as he allegedly squeezed off shots from a shotgun.

But for some reason, that door was locked.

“That door is normally never locked from the inside out … For whatever reason that day it was jammed,” recalled Messenger, his eyes red and watery. “As soon as that happened, that signaled to me, ‘OK, this is intentional. Those are shots.'”

He added, “We see things on the news all the time, so unfortunately, we’re kind of desensitized to them. I quickly recognized, oh, this is a malicious situation, he’s here to do harm to us.”

The pair dashed to a desk in a far back corner of the office and hid from the gunman.

That’s where Messenger dialed 911 twice — but didn’t dare speak to the operator for fear of tipping off Ramos to their whereabouts.

Instead, the quick-thinking intern texted his friend to call the police.

He then gave his cell to San Felice, who had left her own phone at her desk.

“The only solace was, here Selene, you can have my phone, text whoever you need to text, contact whoever you need to contact,” Messenger said. “She texted her mother … and then she proceeded to send the tweet.”

Using Messenger’s Twitter account, San Felice tweeted the first alert that the newsroom was under attack.

“Active shooter 888 Bestgate please help us,” the post said.

Messenger said he’s unsure whether he’s going to continue his internship at the paper, which valiantly published its Friday edition amid the shooting tragedy.

“At the moment, I’m not sure. I’m still trying to decompress,” Messenger said.