Stumbled ahead of April jobs report

The day started on an optimistic note, as a decline in weekly jobless claims ahead of the April jobs reading, due Friday morning. But shortly after the opening bell, investors were hit with a weaker-than-expected reading on the U.S. service sector. If the upcoming reports continue to trend negative, that would throw a pebble in the Fed's decision basket for taking some action. European Central Bank officials voted Thursday to hold interest rates steady, even as the euro-area economy slides toward recession.  Investors also continued to sort through a deluge of Q1 corporate results. GM fell more than 2% after the automaker reported strong first-quarter earnings on good results in its domestic market, but took a hit on its bottom line from rising losses and special charges in Europe.