"Now on the first day of the week, when the disciples came together to break bread, Paul, ready to depart the next day, spoke to them and continued his message until midnight. There were many lamps in the upper room where they were gathered together. And in a window sat a certain young man named Eutychus, who was sinking into a deep sleep. He was overcome by sleep; and as Paul continued speaking, he fell down from the third story and was taken up dead. But Paul went down, fell on him, and embracing him said, 'Do not trouble yourselves, for his life is in him.' Now when he had come up, had broken bread and eaten, and talked a long while, even till daybreak, he departed. And they brought the young man in alive, and they were not a little comforted" (Acts 20:7-12).
After arriving in Troas, Paul and the other Christian men certainly encouraged some of the disciples during the week. When Sunday came (the first day of the new week), they assembled with all of the Christians in that area for worship and edification. Although it is traditional for American congregations to gather both in the morning and evening on the Lord's day, it appears that in Troas the disciples were in the habit of coming together in the evening (perhaps after working all day). The stated purpose for their gathering was "to break bread." Contextually, I believe this refers to the Lord's Supper memorial (i.e., communion; cf. Acts 2:42; I Cor. 11:20-29). That was the fundamental reason why they assembled; namely, to remember Christ's suffering and death on the cross! While gathered for such, other aspects of worship were also participated in (e.g., singing, praying, preaching, and giving; e.g., Col. 3:16; Acts 12:12; 20:7; I Cor. 16:1,2). On this occasion, after they participated in the Lord's Supper, the apostle Paul spoke until midnight. This is one reason why it appears their assembly started on Sunday evening (which would result in a sermon length of several hours perhaps as opposed to half a day or more!). Paul was planning to depart the next day (i.e., Monday). One reason, no doubt, for the length of his address was that he was not planning to return to this area again. As one who loved them dearly, he had much to tell them and remind them of.
The upper room in which the church assembled contained many lamps. Why is this detailed shared by Luke? It is impossible to know for certain, but perhaps it is mentioned as part of the reason for the "deep sleep" Eutychus fell into. Was it fumes or low oxygen that contributed to Eutychus' sleepiness, or was it simply too late for the young man? Regardless, as a preacher I can take a little comfort in the fact that even the great apostle Paul, who preached via inspiration of the Holy Spirit, sometimes had those in the assembly fall asleep as he taught!
Eutychus' fall from the third story certainly disrupted the assembly. Paul stopped preaching and went down to where his body lay. Those who reached Eutychus first realized he was dead. However, Paul falls on the boy, embraces him, and modestly says - "Do not trouble yourselves, for his life is in him." Eutychus had actually died, but Paul had brought him back to life by the power of God. The young man is brought back to the assembly later and everyone is greatly "comforted" to see him, which would imply that he is not brought in crippled or seriously injured from his three story fall.
After raising Eutychus, Paul returned to the upper room, ate a meal, and visited with the brethren until "daybreak" (evidently finding it difficult to leave them). Chronologically speaking, there is proof in Acts 20:11 that the Roman method of reckoning time is being used by Luke (i.e., a day begins and ends at midnight, instead of the Jewish method of marking a new day at sunset). Some have incorrectly asserted that this assembly in Troas gathered on Saturday night (Roman time), which would have been the beginning of Sunday in Jewish time. This cannot be correct since Paul intended to depart "the next day" (20:7) and he left in the morning just hours after healing Eutychus. Under the Jewish method of reckoning time, this would mean Paul left later that same day (Sunday), which cannot be correct. The Roman method of reckoning time makes sense here; that is, the church assembled on Sunday night, shared the Lord's Supper, listened to Paul preach until the early hours of Monday morning, and then saw him off after he healed Eutychus, ate a meal, and visited with them some more until daylight.
As a side note, why did the church assemble on the first day of the week? Because of apostolic example and command (cf. I Cor. 16:1,2). The apostles were led into all the truth by the Holy Spirit, and if they taught the early church to assemble on Sunday for the Lord's Supper, contribution, and other aspects of worship, then we should follow their example. The church in Troas assembled every time the first day of the week came around (just as the Hebrews of old were expected to rest on the Sabbath day every time it came around; cf. Exo. 20:8). For an individual or group of disciples to purposely avoid assembling with the church each Sunday and thereby failing to share in the Lord's Supper each Sunday (among other things) is improper.