Am I interpreting the usage of the 「と」particle incorrectly in this passage?

Hi all —

I'm reading through an NHK Easy article about earthquake survivors' experiences. I'm getting tripped up by the usage of 「と」in this one sentence:

男性は「タンスが倒れて、母と弟が亡くなりました。倒れないように、タンスを壁にしっかりと止めていたら、助かったかもしれません。」

Here, 「倒れないように、タンスを壁にしっかりと止めていたら」I'm understanding as 'If the cabinet was securely fastened to the wall to prevent it from falling'. How does the usage of と factor in this sentence? It doesn't make sense (to me) to interpret the particle as 'with' since 「壁に」is already present. However I don't exactly interpret it as indicating a strong causal relationship either due to the -tara conditional form that follows shortly after.