英语翻译

题目

英语翻译
The Ministry of Transport said more than 200 relief workers who were repairing roads had been buried in mud flows over the past three days as well as construction equipment.
为什么flow要加s,希望给出句子的结构分析，
还有一句：China's disaster relief authority has asked for domestic and international help in getting quake-related data collected by satellites to aid Sichuan relief operations.

答案

运输部门声称,在过去三天里,有200多名正在维修公路的援救工作人员及建筑设备被埋入泥石流里