Attorney General Janet Reno yesterday took full responsibility for the decision to shoot tear gas into the Branch Davidian compound. She said she approved the action last week after "totally frustrated" FBI negotiators concluded the cult would not voluntarily surrender.

But after a tense, daylong ordeal in which top federal law enforcers watched in horror as fire engulfed the frame buildings, Reno and senior Clinton administration officials acknowledged a series of miscalculations and misjudgments. While saying the FBI considered "every possible . . . option" and moved carefully, Reno said she never anticipated that the attempt to "ratchet up" the pressure on the compound would provoke such a sudden, violent response from the cult.

"Today was not meant to be D-Day," Reno told reporters at a Justice Department news conference. ". . . Obviously, if I thought the chances were great of a mass suicide, I would never have approved the plan. Everything that we were told, every indication of the reactions to the pressure up to that point, was that that would not occur."

FBI Director William S. Sessions said last night that the bureau "misjudged" cult leader David Koresh. "We had been assured both from our own evaluations of David Koresh, from psychologists, from the psycho-linguists . . . from his assertion himself, repeatedly, that he did not intend to commit suicide," Sessions told CNN. "Yes, it is a surprise that he would do it."

But even as Reno defended the government's actions as a reasonable approach under trying circumstances, questions were being raised about why the FBI decided to move when it did and whether there was adequate planning to handle all the possible contingencies. Some federal law enforcement officials said there had been no imminent danger to the lives of cult members that would have justified an immediate, dramatic escalation of tension in the standoff.

At the same time, some federal agents questioned why the FBI did not bring in local firefighters before the tear gas was used to deal with the prospect of a conflagration. Waco, Tex., fire officials said they learned of yesterday's battering and gassing of Koresh's Ranch Apocalypse only after the FBI called 911 for help.

FBI officials said yesterday they chose not to inform the fire department in advance for "security reasons," noting that the firetrucks could not have withstood the potential fusillade from the cult's arsenal, which officials have said includes .50-caliber ammunition. Therefore, no rapid response team was on hand to cope with the fire.

"There was nothing we could do," R.G. Wilson, Waco's assistant fire chief, said in a telephone interview. ". . . We hadn't been notified. I don't think they {FBI officials} were expecting this. . . . They don't have any fireplugs {at the compound site}. The closest fireplug is probably about 10 miles away. The only available water they had was well water."

White House officials acknowledged that Reno had briefed President Clinton on Sunday about the planned action. But in an apparent effort to minimize his role, Clinton later issued a statement emphasizing that the plan had been "recommended" by federal law enforcement agencies. "The attorney general informed me of their analysis and judgment and recommended that we proceed. . . ," Clinton said. "I told the attorney general to do what she thought was right, and I stand by that decision."

"I made the decision," Reno said at her news conference. "I'm accountable. The buck stops with me." Asked about her consultation with the president on Sunday, Reno added: "I told him what the options were. I told him I had carefully studied and reviewed it and I thought this was the best way to proceed. His statement to me was, 'Well, okay.' "

Reno emphasized that she was intimately involved in the decision-making on yesterday's plan. The idea was first brought to her about a week ago by Sessions; Larry A. Potts, chief of the FBI's criminal division, and other senior officials.

She said she asked a range of questions and satisfied herself that the bureau had taken all reasonable precautions. Doctors assured her tear gas was "not lethal" and would not have posed any danger to the children. Although most if not all of the adults were known to have gas masks, Reno said officials hoped the gas infusion would increase the discomfort level inside the compound.

Reno said she concluded that the use of a modified tank with a battering ram to punch holes in the compound's wall and inject the gas "would be the least intrusive manner possible of trying to resolve this matter without a frontal assault, without the FBI having to return fire."

But Reno and White House officials offered a variety of sometimes conflicting explanations to the most persistent and crucial question: Why, after the 51 days of fruitless negotiations with the apparently unstable Koresh, did the government decide to act when it did?

A key factor, Reno said, was concern that the FBI hostage rescue team was suffering from fatigue and there was no adequate backup to relieve it. FBI experts advised Reno that the team needed "time off, and what I was told is that there were no backups," she said.

Reno later said in response to a question that the FBI believed that "babies were being beaten" inside the compound, a theme later repeated by White House aides. But Reno also acknowledged that, while reports of abuse of children had led to the original Feb. 28 Bureau of Alcohol, Tobacco and Firearms raid on the compound that left four federal agents and perhaps as many as six cult members dead, she was uncertain whether the bureau had information that the beatings were continuing.

At bottom, however, there was an undercurrent of exasperation among the FBI team. For weeks, agents had been seeking to reason with and cajole Koresh into ending the standoff. Simultaneously they used psychological warfare techniques, including cutting off telephone calls into the compound, illuminating it with high-intensity floodlights at night and, over loudspeakers aimed at the compound, playing loud, annoying music, the sound of locomotives and of rabbits being slaughtered.

Nothing worked. Koresh made several promises or suggestions that he was about to leave; he broke each promise. Most recently he said he would come out after he completed a manuscript describing the Seven Seals of the biblical apocalypse. He said he had written the first of the seven-part exegesis, and on Saturday federal officials said he had asked for a word processor and batteries to speed production of the other six chapters.

"Our experts . . . said that they were totally frustrated, that they were not able to negotiate anything with Koresh, that they did not think he would ever come out," Reno said yesterday.

An FBI official, speaking on condition of anonymity, said it was Koresh's unreliability that finally pushed the bureau to ask Reno for permission to escalate the conflict. "This could have been done last week; it could have been next week," said the official. "But if not today, when? Were we going to sit there and wait for this guy to finish his treatise on the Seven Seals? . . . Were we going to sit there status quo for another month, another two months, another six months?"

One federal official who asked not to be named said the FBI's frustration showed that agents had mistakenly viewed Koresh and his followers as adversaries rather than the "sick, sad people" they were. Instead of getting angry at the cult leader, the FBI could have sought out followers or other religious leaders who might have been better able to relate to Koresh on his own terms.

But another veteran hostage negotiator said yesterday he "sympathized" with the FBI. "There were no easy choices here," said Phil Singleton, a former counterterrorism specialist who was part of a British team that successfully freed 19 hostages from the Iranian Embassy in Britain in May 1980.

"Other than the people coming out and giving up, there was probably no way that this was going to end without people getting injured. . . . You're talking about a cult. You don't know how fanatical they are going to be. . . . I thank God I wasn't the one having to make these decisions. . . . What do you do? What do you do?"

Read the Tribune-Herald's 7-part investigative series on the inner workings of the Branch Davidians. Hours after Part Two appeared in print, the ATF raided the group's compound.

Read the Tribune-Herald’s account of the ATF raid on the Branch Davidian compound on Feb. 28, 1993. Four ATF agents and six in the compound were killed in the gunfight.

Read the daily news accounts of the 51-day siege at the Branch Davidian compound near Elk, which began Feb. 28 and lasted until April.

Read the accounts of April 19 and beyond: FBI agents began inserting canisters of tear gas into the Branch Davidian compound in the early morning hours. By noon, it was on fire.