He had been guarding the U.S. Embassy in Ankara, as he'd done many other days -- with commitment and professionalism. She had gone there to have tea with the ambassador, a respected television journalist set to renew acquaintances with a diplomat and do her job.

Then came the blast.

Whether or not they'd crossed paths before, these two people's stories now forever will be intertwined -- thanks to a man Turkish authorities say belonged to the Marxist Leninist organization known as the Revolutionary People's Liberation Party, or DHKP-C, which the U.S. government and others label a terrorist organization.

Ecevit Sanli, as he was identified by Istanbul police, died after detonating his bomb near the embassy's Gate No. 2 around 1:15 p.m. (6:15 a.m. ET) Friday.

So, too, did the Turkish guard -- described by U.S. Ambassador Francis Ricciardone as a "hero," and identified by Turkey's semi-official Anadolu News Agency as Mustafa Akarsu.

A photo showed the journalist being carried away on a stretcher, apparently bleeding. Rather than sitting with her for tea, Ricciardone visited the woman -- Didem Tuncay -- at Ankara's Numune Hospital, and afterward described her as "one of the best."

While theories have been floated, neither Turkish nor U.S. authorities have detailed why they think Sanli blew himself up. Prior to Friday, he was known to U.S. and other intelligence agencies, a U.S. law enforcement source told CNN.

Whatever Sanli's rationale, the explosion spurred security clampdowns at diplomatic facilities in Turkey, plus messages of condolences and solidarity. Turkish Prime Minster Recep Tayyip Erdogan called it an attack "against the peace and welfare of our country."

Yet the violence reverberated well beyond Turkey's borders, however, especially in the nation whose embassy was targeted.

The spotlight on U.S. diplomatic installations was already intense after violence last September in Egypt, Tunisia and Libya, where Ambassador Christopher Stevens was one of four Americans killed in Benghazi.

U.S. Rep. Ed Royce said Friday's explosion in Turkey served as "yet another stark reminder of the constant terrorist threat against U.S. facilities, personnel and interests aboard."

"Coming after Benghazi, it underscores the need for a comprehensive review of security at our diplomatic posts," said Royce, a California Republican and chairman of House Foreign Affairs Committee.

'He exploded at the guard'

The bomber had first gone to the rear access of the embassy, then went to a checkpoint on the building's perimeter where IDs are checked, explained U.S. State Department spokeswoman Victoria Nuland. According to law enforcement sources working on the investigation, Sanli blew himself up on a walkway for embassy employees and their guests.

"He exploded at the guard," Nuland explained.

The guard, Akarsu, on one side of the security barrier was killed. Two guards on the other side of the glass survived, said the State Department spokeswoman.

The blast blew a hole in what appeared to be a building that is part of the compound's outer gate, images from CNN sister network CNN Turk showed. This was all part of a large complex that includes blast doors, reinforced windows and a series of metal detectors that visitors must navigate before reaching embassy offices.

The attack stirred swift condemnations, as well as fresh security precautions. The U.S. Embassy in Ankara subsequently put out a statement telling Americans not to visit that facility or U.S. consulates in Istanbul or Adana "until further notice."

Portions of Paris Avenue, where the targeted embassy is located, were shut down, according to Anadolu news. Germany and France, meanwhile, were among the countries who tightened their security in the wake of the blast.

The U.S. ambassador said in a statement that he'd "paid my respects to the family of the Turkish hero who stood guard for us every day."

Calling him "well trained (and) committed to his job," Ricciardone praised the late guard as a "good, excellent, professional guard" who "died defending the Turks and the Americans who work at the embassy."

The ambassador also talked about visiting Tuncay, whom he recalled was "the first person to interview me when I arrived two years ago at NTV." Having learned she'd recently left the Turkish network, Ricciardone said he invited her to tea.

"She serves her country by getting the truth to the Turkish people," the ambassador said. "She, I think, is one of the best."

Not first brush with terror for Turkey, U.S.

Friday's blast was hardly Turkey's first brush with terror.