My wife and I were on #14 when it derailed in Hayward, CA on 8/21 at about 10 p.m., so I can give you a first-person account of what went on. What has been printed in the Bay Area media is generally correct, however I would like to add some clarifications. The train consisted of three locomotive units [the lead unit was a California Amtrak unit, the others Amtrak Genesis units], one baggage car, four Superliner sleepers, the Pacific Parlor car, diner, sightseeing lounge and 5 Superliner coaches [in that order from front to rear].
The "unknown object" on the tracks that caused the derailment was apparently a drawbar that had been dropped between the rails. [i was told this privately by an Amtrak supervisor] There were three locomotives on the train. The first two units passed over the drawbar without incident, but the rear truck of the third unit caught it and derailed. The baggage car and the first [transition] sleeper also derailed and were jacknifed to the left. All other cars remained in line. The drawbar ripped out plumbing from underneath the sleeper and gouged a dent in the floor of the car. [Occupants of this car described a loud "scraping" noise and how the floor of the car heaved upwards. The two additional cars that derailed were the 3rd and 4th of the 5 coaches.
The incident took place in a industrial area of Hayward near a street crossing and adjacent to several other access points that could be reached by emergency personnel. Fire and police were on the scene within 10-15 minutes. Initially we were told to remain in our seats. However, the derailment had caused a loss of power to the train from the lead locomotive unit rearward. Ventilation fans quit and service lighting went out immediately. We were in the second coach and other than an abrupt stop and clouds of dust outside, we initially assumed it was just the most abrupt, unexplained stop of several we had experienced since leaving San Luis Obispo.
Emergency lighting began to fail as batteries were exhausted. We were told to leave the train and move outside onto the right of way [which was level and about 100 feet wide at that point. We milled around for well over an hour. Amtrak responded quite well, eventually dispatching about 7 buses to the scene and took all the passengers to the Oakland station at Jack London Square. Passengers to SF, Emeryville and Martinez were bused to their destinations. Most of us going farther were bused to Sacramento, however Amtrak was unable to secure enough buses to accomodate all those going that far. My wife and I spent the night in the Oakland station along with about 50 others and we took the first CalTrans commuter train of the morning to Sacramento.
In Sacramento southbound #11 was terminated. Passengers were put on San Joaquin trains for LA. The others going south of the Bay area were probably bused--although I don't know for sure. The equipment from #11 was cleaned, we were loaded. The train backed out of the Sacramento station about 10:45 a.m., turning on the wye where the line to Chico intersects the Overland Route that leads to Roseville and proceded northward without further incident. I noted that unlike our trip from San Luis Obispo to San Jose, UP put all the freights "in the hole", allowing us to avoid the interminable waits that too often plague this train's operation.
Returning to the "unknown object" that was on the tracks and caused the derailment: Several sources spoke of similar, but not so serious, incidents that had happened in the Bay area, apparently over the past several years. However, the Amtrak supervisor I spoke with put it this way. He said that a drawbar on the tracks can come from one of two sources. First, it could have fallen from a passing freight train. However, freight trains do not carry unsecured, spare drawbars on, say, a flatcar. If this had been the case, the drawbar would have ended up off the tracks, because if it had fallen between the rails it would have derailed the remainder of the freight. Next, assume the drawbar had been pulled out of its socket while a freight was in operation. Then the drawbar could have fallen between the rails, but the rear portion of the freight train would have been detached. There had been no reports of freight trains breaking in two that night. The second possible cause that he offered was that "unknown parties" had somehow secured a drawbar and deliberately put it on the tracks. This would have required more than the efforts of one individual. He concluded by saying: "you can draw your own conclusions".
In retrospect, this supervisor's reasoning, along with the alleged history of past vandalism in this area, leads me to believe that this was a deliberate intent to do damage to railroad property, whether UP's or Amtrak's. It is fortunate that there were only 7 relatively minor injuries and that damage to Amtrak equipment was minimized.