Aug. 23, 1975: Bombs are found under two LAPD cars.

To settle the differences, the Daily Mirror turned to Sandi Gibbons of the Los Angeles County district attorney's office, who provided a transcript of testimony on the incident given to the grand jury in 1976. The following account is based on that testimony.

On the night of Aug. 21, 1975, Officers James J. Bryan and John David Hall were working the mid-watch patrol in Hollywood. About 11:15 p.m., the officers stopped to eat at the International House of Pancakes, 7006 Sunset Blvd. Bryan, who was driving that night, said they left about midnight and responded to a radio call.

As the police car was backing out of its parking space, it was seen by a group of friends pulling into the lot, according to Mervin William Morales. Morales testified that he and his friends parked in the spot next to the one vacated by the police and went into the restaurant. Morales said that when they left the restaurant 10 or 15 minutes later, they noticed what might have been a bomb in the vacant space where the police car had been parked. (To clear up one common misconception, the bombs were placed on the ground. Only a part of the trigger mechanism was attached to the police cars.)

Officer McMillen said he and his partner talked to Morales about 12:10 a.m. on Aug. 22, 1975, and arrived at the restaurant five or 10 minutes later.

"I saw what appeared to be the end of a pipe, a plumbing fixture, wrapped in some black plastic or a black covering," McMillen said. He went into the restaurant and made a telephone call to the watch commander to report what happened.

Officers responded to the restaurant, including Bryan and Hall, who were called to handle traffic control at Sunset and Highland as police blocked off Sunset Boulevard and several side streets and evacuated some areas.

About 1:30 a.m., Officer Lawrence L. Baggett arrived at the restaurant. Baggett, of the firearms and explosives unit of the LAPD Scientific Investigation Division, said he was met by a sergeant and investigators who told him about what might be a bomb in a parking space.

Baggett said: "I approached it; performed what we call an initial render-safe. And then called out the rest of my unit to assist me in the transportation of it."

In the meantime, Bryan and Hall had responded to a robbery call at Sunset and La Brea. Bryan said that officers had been informed about the bomb and he decided to look under their car.

"I saw a red U-shaped magnet attached to the frame of the car and attached to the magnet was a piece of fishing line," Bryan said. Shortly thereafter, Baggett went to Sunset and La Brea to examine Bryan and Hall's police car.

About 2 a.m., as part of a general inspection of LAPD vehicles ordered as a safety precaution after the restaurant incident, Officer Martin Joseph Feinmark and his partner, Officer Hohan, checked the black-and-white patrol cars at the Hollenbeck Division. After finding nothing under the marked cars, the officers checked three unmarked vehicles parked on St. Louis Street.

Feinmark said that he found a bomb in a trash bag placed beneath the oil pan of one of the unmarked cars. Baggett and an unidentified officer arrived and as Baggett watched, the other officer disarmed the second pipe bomb.

The Bombs

 The only way to resolve some questions about the SLA pipe bombs was to re-create one (without the explosives, of course). It's an interesting process, one that I won't fully describe for obvious reasons.

Although the bomb wasn't as large as described in initial news reports (The Times said it was about 18 inches long) it was still sizable. The bomb was housed in a foot-long piece of 3-inch galvanized pipe. The volume of the cylinder is 85 cubic inches, a little more than a quart, dry measure. When fully assembled as described in the transcript, including battery, nails and sand in lieu of powder, the bomb weighs about 20 pounds.

These days, the SLA pipe bomb is not something that can be made after a quick trip to Home Depot or even the average plumbing supply store. Tracking down the components was a scavenger hunt and some of them were so hard to find they had to be ordered.

Without revealing all the components, I have to say I was struck by how few nails were used. News accounts say the bomb was "tightly packed" with nails, and although that statement is true, it's misleading. The bombers used about 120 small nails, according to the transcript, a fairly modest amount considering the capacity of the pipe. Clearly, most of the space was used for explosives.

I was also curious about why the bombers used one particular component because it seems to be needlessly complicated, but I don't think I'll be asking them anytime soon.

We do know with some certainty what would have happened if the bomb had exploded. In 1976, according to the transcript, the LAPD reproduced the SLA pipe bomb and blew up an old patrol car with two mannequins inside at El Toro Marine Corps Air Station. The blast was photographed and videotaped, according to police testimony.

Baggett said: "It ripped a big hole in the floor of the vehicle, a number of them. It sent fragmentation through the floor of the vehicle; through the seats and through the roof of the vehicle, all out through the hood of the vehicle. It caused extensive damage to the interior of the vehicle.

"The mannequins, the passenger mannequin was shoved practically up into the ceiling. The driver mannequin was also moved around; distorted."

Baggett said: "had the device been placed under, say, the passenger side of the vehicle, putting the passenger officer directly above it or in extremely close proximity to it, I would say the odds of him being extremely or gravely injured, if not killed outright, would be very good.

When filled with sand and attached to a battery, this re-created bomb weighs 20 pounds.

"And the driver, the other officer, would be sitting to his left; would also stand a very good chance of being severely injured if not killed."

In some of the most chilling testimony, Baggett was asked what would have happened if the bomb had gone off while he was disarming it. He said: "Had I been in the position of trying to render it safe, then — that is, in direct proximity to it, I am sure I would have been seriously injured and I, just from the overall power and the amount of fragmentation and shrapnel, I honestly believe I probably would have been dead."

The big question, of course, is why the pipe bomb didn't explode. Its failure wasn't due to SLA incompetence. The answer is simple mechanical failure of one improvised component of the bomb. The trigger mechanism used two metal contacts placed in the jaws of a wooden clothespin. The contacts were held apart by a small wooden wedge connected by fishing line to a magnet attached to the police car. When Bryan and Hall pulled out of the parking space, the wedge was pulled out of the clothespin, but the jaws closed off-center instead of coming together squarely, so the contacts missed each other.

Footnote: According to Clinton Erickson, an LAPD retiree who tracks the deaths of former LAPD officers, Baggett died in 2006.