—What can I do to fix this?
That is not user-fixable.
—Can it be repaired if I take it to a Mac store?
Unlikely, at least in-store. There are simply too many variants of each Apple product to effectively maintain a sufficient parts inventory in a retail setting.
More and more, Apple stores are sending devices to one of their centralized repair centers that has the techs and a full inventory of parts needed. At least in the US, you can send it yourself and save a day of shipping on each end. Start here:
Mac Repair and Service - Apple Support
and look at the "Send in for Service" option. The center should contact you with an evaluation and either a cost estimate or an "not fixable" decision.
However, your first action should be to put your homeowners'/renters' insurance carrier on notice of a potential loss. Most such policies cover damage to your tech, subject to the usual deductible of course. The chances of your Macbook Air being irreparable or needing costly overhauling are quite high.