prevent from fire 裏

不知你的示句是從哪裏抄下，我也不敢說它錯與否，但在普通的用法下，根據第四版牛津高階字典，它就給予prevent這字的句型是：
Prevent sb/sth (from doing sth)
如：to prevent the spread of a disease, to prevent avian flu
或可說：to prevent a disease from spreading（防止某種疾病的蔓延）
所以，若想講防止火災，其實只要說成prevent fire就可以，並不需prevent from fire
如：We must take extra precaution to prevent fire(我們需要採取額外的措施去防止火警。

2007-05-30 10:04:02 補充：
其實from不但有從這個意味，它還有離的意思，並免掉、去除、阻止的意思（它的其他意思你可以參考yahoo字典）如：Our school is 2 miles from the station(我們學校離車站兩里）　　It will keep you from danger(它會防止你發生危險）

actually I think there is no "prevent from fire"
rather, we can say "prevent fire from happening" or just prevent fire

that is, prevent + sth + from + verb-ing

so, I think there is a problem in your sentence