Unexpected End of FIle When Reading Large Files into Node.js with ReadStream and Lazy

Background

I am assisting on a project analyzing the volume of Twitter conversation about games in the 2013 NCAA Men's Basketball Tournament. We collected tweets using the a simple Node.js request and the Twitter Streaming API's Status Filter method and saved the response in plain text files. So far we have collected about 15 million tweets that take up about

Now we are attempting to process these tweets and upload only the relevant information (uid, timestamp, text, and language) into a MongoDB database using another simple Node.js script, shown in this Gist which also has a very small sample of raw tweets we've collected. Once the tweets are loaded into the database, we will be filtering and aggregating them to export the information we need.

Problem

So here's the issue: When the script to save the tweets in the DB is run it throws an unexpected end of file error and dies. I have verified that the ReadStream and an instance of Lazy have been initialized, the problem seems to be happening when the script tries to act upon each line and parse the line into a valid JSON object.

Any thoughts on why this is happening or how to fix it?

Example Stack Trace

undefined:1
3","indices":[3,10]}]},"favorited":false,"retweeted":false,"filter_level":"low
                                                                          ^
SyntaxError: Unexpected end of input
    at Object.parse (native)
    at /home/ubuntu/ncaa/savetodb.js:31:34
    at Lazy.<anonymous> (/home/ubuntu/ncaa/node_modules/lazy/lazy.js:91:13)
    at Lazy.<anonymous> (/home/ubuntu/ncaa/node_modules/lazy/lazy.js:73:19)
    at Lazy.EventEmitter.emit (events.js:95:17)
    at yieldTo (/home/ubuntu/ncaa/node_modules/lazy/lazy.js:181:18)
    at Function.<anonymous> (/home/ubuntu/ncaa/node_modules/lazy/lazy.js:219:25)
    at Lazy.<anonymous> (/home/ubuntu/ncaa/node_modules/lazy/lazy.js:187:21)
    at Lazy.EventEmitter.emit (events.js:95:17)
    at ReadStream.<anonymous> (/home/ubuntu/ncaa/node_modules/lazy/lazy.js:50:22)