Excerpts from the book "12 Days of War: Israel vs. Iran"
...Each squadron had its own set of targets, both primary and secondary. Intelligence spent considerable time studying the personalities of those to be eliminated in order to accurately calculate the attack strategy. This included their bedtime, whether they used the restroom or smoked at night, which room they slept in, and other behavioral characteristics. The goal was not only to eliminate the targets but also to avoid harming (or at least minimize) civilians.
...General Ali Hajizadeh, commander of the IRGC Aerospace Force, received information from Hezbollah about an impending Israeli strike. He convened a meeting of his command group in a bunker outside Tehran, which was immediately reported to AMAN, Israeli military intelligence. Some of the aircraft, armed with bunker buster bombs, were diverted there. At a tremendous altitude, the first wave of 140 aircraft approached Iranian airspace. Various measures, radio silence, and electronic warfare allowed this to be accomplished completely undetected by the Iranian air defenses.
Half an hour into the meeting, Hajizadeh concluded that the alarm was false; the radars from which the crews were feeding information into the bunker were clear. The general decided to send everyone home; the information received from the Lebanese was not confirmed.
We don't know for sure how exactly AMAN was monitoring Hajizadeh, whether he had an agent or a bribed officer nearby, or whether the bunker was wiretapped, but Israeli intelligence knew what was happening in the command center, in real time, so to speak.
An intelligence officer reported to the commander of the Israeli Air Force, General Bar, that Hajizadeh was sending his subordinates home, and that everyone would soon be gone. A decision had to be made, and it had to be made quickly.
General Hajizadeh was the man who would have given the order to retaliate in the event of an Israeli attack. He headed the IRGC missile project.
Tomer Bar, the commander of the Israeli Air Force, had barely a couple of minutes.
The success of an operation, arguably the most important in the country's history, was at stake.
The tension in the Air Force command post was so intense it was almost tangible, like an electric field.
"Turn on the IFF transponders," Bar commanded.
140 aircraft simultaneously appeared on Iranian radar screens. Hajizadeh realized the airstrike was coming after all and, along with his subordinates, remained in the bunker, where, fifteen minutes later, he was literally buried.
At approximately 3:30 AM, bombs began exploding in the apartments of other Iranian generals. It took the Israeli Air Force 12 minutes to literally wipe out the entire senior command of the IRGC and the Iranian army.
On the first day of the war, Iran completely lost military control, and for many hours there was simply no one to give the order for a retaliatory strike. Around 10:00 a.m., the Iranians launched a hundred drones, but all were shot down before entering Israeli airspace...