See "Navel in Buddha" on Academia.edu https://www.academia.edu/43042460/Navel_in_Buddha. Text is quoted verbatim. Multiple internet sites show the same text, but only this one appears to be a more reliable source.
Gopal, Madan (1990). K.S. Gautam (ed.). India through the ages. Publication Division, Ministry of Information and Broadcasting, Government of India. p. 176.
Mahâbodhi, or the great Buddhist temple under the Bodhi tree at Buddha-Gaya, Alexander Cunningham, 1892: "I next saw the Tree in 1871, and again in 1875, when it had become completely decayed, and shortly afterwards, in 1876, the only remaining portion of the Tree fell over the west wall during a storm, and the Old Pipal Tree was gone. Many seeds, however, had been collected, and young scions of the parent tree were already in existence to take its place."
For more on the topic see also the chapter "Buddha, Buddhism, and the bodhi tree" in Belief, Bounty, and Beauty by Albertina Nugteren. doi:10.1163/9789047415619_004
