toyota corolla 2004 engine

While driving 70 mph on the expressway, the engine gave a quiet jolt and
started losing power, and I needed to pull over pretty quickly. We don't have
much car maintenance knowledge but we looked through the book, checked
the coolant level and it looked empty. When our tow truck arrived, he added
water to the empty coolant tank and he tried to start it up. The engine failed to
start, but did make slow efforts to turn over. The tow truck driver thought it
was the starter or alternator. I had no idea what was involved with either
issue, but took it to a Firestone repair place. Very quickly the mechanic told us
that out engine was shot. He said something about the timing chain breaking
and doing internal damage. Few other details that made sense to us, but we
didn't know what to ask except what would it cost to repair. A new engine, if it
could be found for a 2004 model, plus labor would be roughly $4,000. The car
has about 130,000 miles on it. One mechanic said he was surprised that the
timing chain gave out at such a low mileage. The repair shop owner offered to
'dispose' of the car, but I needed to send him the title. I'm feeling a little
suspicious and not sure what other inquires to make before giving up on the
car.