Emergercy situation( using the past tense and past continuous )

Teresa was going downstairs to the laundry, when Auntie Tin fell down in her flat.

When Teresa was knocking on her door, no one opened and answered.

Teresa called the ambulance to rescue Auntie. Tin.

And then ambulance took Auntie. Tin with her daughter Helen.

Teresa was explaining about the accident while her neighbours were listening.