Over the weekend, many Times readers responded to Friday's Metrolink disaster; Tuesday's letters feature some of their thoughts.  Paul Sailer of Los Angeles sums up the reaction well:

It is almost inconceivable that Metrolink depended only on human response to a red light to keep two trains, hurling toward each other at high speeds on a single track, from colliding...

Hopefully this horrific tragedy will inspire Metrolink and other passenger railroad systems to install ... fail-safe [safety] devices.

There were reactions, too, to Sunday's story about lies on the campaign trail -- how, readers ask, can the Times compare the McCain camp's doozies with Obama's milder misstatements?  Thoughts on the war in Afghanistan, too. 

*Photo of Metrolink rider on Monday by Nick Ut/AP.