Engine died while crossing RR tracks

The distributor connector is a "good place" for trouble, because there is almost no current flow there. It can corrode.

Wiggle and work all the ignition connectors in and out several times. Distributor, ECU, ballast.

It would have been better if you had tried to fix it "right then" so to speak, but I realize...........

Also I believe these cars had a big WHITE connector under the hood, connecting the engine harness to the firewall section of the harness. These are subject to failures.

One test you can do "when fails" is to leave the key in "run," remove the distributor connector, and tap the bare end of the 2 pin firewall side of that connector to ground. Each tap should generate one spark. If so, might be the distributor or that connector.

If not, ECU problem or other wiring connections. Make absolutely certain ECU is grounded

Coil + should have something around 5--9V with key "in run." Below 5 indicates a voltage drop problem, nothing a wiring problem or bad ballast, 12V is ECU problem or ungrounded, or bad coil.

Under same conditions, coil NEG should have low voltage, perhaps 1V. Nothing at all is a problem, 12V means the ECU is not causing the coil to conduct or ECU is not grounded.