WordPress Site Down

Hi,

Recently we started our wordpress blog and had around 26 live post in just three weeks. But two days back site went down.

After contacting our hosting service provider( on recommended list of wordpress.com), we were told that our .htaccess file may have been changed. After confirming for the same, we realized that .htaccess was modified at time when site was up and running and continued to do so well beyond that time.Also our hosting provider proposed removing .htaccess file as possible.Did that as well but to no effect.

This is a strange issue as error crept in at time when no file was modified.One of our team members runs an alternate technology blog but has faced no issue like this before.

Please suggest some possible measures.

Thanks